About TheCalculatorHive

TheCalculatorHive is a growing collection of free online calculators. We started with finance — where small modelling errors cost real money — and we are expanding across loans, health and everyday math. Every tool is built to be quick to use, mobile-friendly, and correct to the last decimal.

The web is full of calculators, but too many are slow, cluttered with pop-ups, or vague about how they reach a figure. We set out to build the opposite: tools that load instantly, explain their working, and show you the full schedule behind every headline number — so you can trust the result and learn something while you are at it.

What makes us different

• Accuracy first. Our math runs on a tested engine — the same numbers you would get from a spreadsheet or a bank statement, not a rough approximation. Every release is gated behind an automated test suite so the figures cannot quietly drift.
• Clear results. Headline figures, charts and full period-by-period breakdowns, so you can see exactly how a number was reached — and each tool comes with a plain-English explanation and worked examples.
• Fast and private. Pages are pre-rendered and served from a global network, so they open in a blink. We require no account and ask for no personal details to use the tools.
• No sign-up, no paywall. Everything is free to use and shareable with a single link that captures your exact inputs.

How our calculators work

Each calculator updates live as you type — there is no “submit” step to wait on. The numbers you enter are sent to a stateless calculation service that returns the result and the full schedule, which we render into the table and charts you see. Nothing you enter is stored or linked to you; the only place your inputs persist is the shareable link in your address bar, which you control. The worked examples in each article are generated by the very same engine that powers the live tool, so the educational content can never disagree with the calculator.

Available now

• Compound Interest Calculator — Future value, total interest and APY with optional regular deposits, withdrawals and a full breakdown.
• Simple Interest Calculator — Final balance, interest accrued and end date using the classic I = P × r × t formula, with optional deposits and withdrawals.
• Daily Compound Interest Calculator — Future value with interest compounded daily — including weekend exclusion, partial reinvestment and optional deposits or withdrawals.
• PPF Calculator — Public Provident Fund maturity value, total interest and a year-by-year breakdown, with the ₹1.5 lakh yearly limit and 15-year tenure.
• FD Calculator — Fixed deposit maturity value, interest earned and year-by-year growth from the deposit amount, rate, tenure and compounding frequency — quarterly, monthly, half-yearly or yearly.
• Inflation Calculator — See the future value of money and its purchasing power over time — the future cost of an amount and what a fixed sum is worth in today’s money — from an average inflation rate or two CPI index values, with a year-by-year chart. Supports deflation.
• ROI Calculator — Calculate return on investment — your total (simple) ROI and the annualized ROI (CAGR) — plus net gain and investment multiple, from a cost, a final value and a holding period. Multi-currency, handles losses, and compares investments held for different lengths of time.
• Discount Calculator — Work out a sale price, the amount saved, the original price or the true percentage off — for a single discount, a fixed amount off, or a stack of successive discounts — and add sales tax. Stacked discounts compound (they do not add) and the discount is applied before tax. Multi-currency.
• Future Value Calculator — Project the future value of money — a present-day lump sum, a stream of regular contributions, or both together — at a chosen rate and horizon, with ordinary-annuity vs annuity-due timing and a year-by-year growth chart. The textbook time-value-of-money closed form, multi-currency.
• Investment Calculator — Project the future value of an investment — an initial lump sum, regular contributions, or both together — at a chosen return rate, compounding frequency and horizon, with ordinary-annuity vs annuity-due timing and a year-by-year growth chart. Multi-currency, live, no sign-up.
• Retirement Planning Calculator — Find out if you are on track to retire. Project your nest egg from current savings and monthly contributions, then compare it to the corpus you need under the 4% / 25× safe-withdrawal rule — inflation-adjusted, with a year-by-year growth chart and a surplus-or-shortfall verdict. Multi-currency.
• RD Calculator — Recurring deposit maturity value, interest earned and year-by-year growth from your fixed monthly deposit, interest rate and tenure — quarterly compounding, the Post Office and bank convention.
• Old vs New Tax Regime Calculator — Compare India's old and new income tax regimes for FY 2025-26, see your tax under both, your savings, and which regime to choose.
• GST Calculator — Add GST to a price or reverse it out of a GST-inclusive total, and see the CGST + SGST (intra-state) or IGST (inter-state) split for any rate — 5%, 12%, 18%, 28% or custom.
• Cash Back Calculator — Work out how much cash back a credit card earns — a flat rate or tiered categories with bonus-spend caps — subtract the annual fee for your net benefit, and see your blended effective cash back rate.
• Risk Reward Calculator — Calculate the risk:reward ratio of any stock, forex or crypto trade from your entry, stop-loss and target prices. See the “1 : X” ratio, total risk and reward for your position size, the breakeven win rate you must clear, and your expected P&L per trade — for a long or short.
• Options Profit Calculator — Calculate call and put option profit at expiry for long or short positions. Enter the strike, premium, lot size and underlying price at expiry to get your total P&L, break-even price, maximum profit and loss, return on premium and an interactive payoff diagram. Single-leg, intrinsic value at expiry — works for US and NSE India options.
• Position Size Calculator — Work out exactly how many shares to buy or short on a trade so a stopped-out loss stays within 1–2% of your account. Enter account size, risk %, entry and stop-loss to get the share count, max loss, capital required and dollar risk — for a long or short, in any currency.
• Average Price Calculator — Calculate your quantity-weighted average price per share across multiple buy lots. Add each purchase (price and quantity) to get your blended cost basis, total investment, fee-free break-even and unrealized P&L — the right way to model averaging down a stock, ETF or fund position.
• APY Calculator — Convert a nominal interest rate and compounding frequency into the effective annual percentage yield (APY), and see the one-year interest earned and ending balance for any principal.
• CAGR Calculator — Calculate the compound annual growth rate (CAGR) between a beginning and ending value over any period — plus total (absolute) return, growth multiple and total gain, with a year-by-year implied-growth chart. Multi-currency, handles declines and fractional years, and annualises returns so investments held for different lengths of time compare fairly.
• SIP Calculator — Project the maturity value, total invested and estimated returns of a monthly SIP (systematic investment plan) in a mutual fund, with a year-by-year growth chart.
• Lumpsum Calculator — Project the maturity value, invested amount and estimated returns of a one-time lumpsum mutual-fund investment from your amount, expected return and tenure, with a year-by-year growth chart.
• SWP Calculator — Plan a Systematic Withdrawal Plan: see your remaining corpus, total withdrawn, return earned and the exact month your money runs out from a lump sum, monthly withdrawal, expected return and tenure, with a balance-over-time chart. Matches Groww and ClearTax.
• NPS Calculator — Project your National Pension System (NPS) retirement corpus, lump sum, annuity amount and estimated monthly pension. Enter your age, monthly Tier-1 contribution, expected return and annuity rate — with the annuity-due formula, the 40% minimum annuity and the 60% tax-free lump-sum rule.
• Hourly to Salary Calculator — Convert an hourly wage to an annual salary — or a salary back to an hourly rate — and see the daily, weekly, biweekly and monthly equivalents. Uses the 2,080-hour full-time rule (40h × 52wk), handles part-time and unpaid weeks, and works in any currency. Gross, pre-tax figures.
• Salary Hike Calculator — Calculate a salary hike three ways: find your new salary after a raise, work out the hike percentage between an old and new salary, or back-calculate the old salary from a new figure — plus the increment amount. Hike % = ((New − Old) ÷ Old) × 100, works in any currency, gross pre-tax figures.
• Gratuity Calculator — Calculate the gratuity payable in India under the Payment of Gratuity Act, 1972 — the ÷26 (covered) and ÷30 (not covered) formulas, the >6-month round-up, the ₹20 lakh statutory cap and the Section 10(10) tax exemption. Enter your last drawn Basic + DA and years of service.
• Salary Calculator (CTC to In-Hand) — Convert your annual CTC into monthly and annual in-hand (take-home) salary for India. See the full breakup — basic, employer PF, gratuity, gross, employee PF, professional tax and new-regime FY2025-26 income tax — with adjustable basic %, PF basis and tax basis.
• HRA Exemption Calculator — Calculate the House Rent Allowance exempt from income tax in India under Section 10(13A) read with Rule 2A — the least of actual HRA received, rent paid minus 10% of salary, and 50% (metro) / 40% (non-metro) of salary. See which limb caps your exemption and how much HRA stays taxable. Old tax regime only.
• Retirement Calculator — Find the retirement corpus you need and whether you are on track — from your age, monthly expenses, inflation and expected pre- and post-retirement returns. Uses the inflation-growing present-value method, shows the surplus or shortfall, the monthly SIP to close the gap, a 25× / 4%-rule sanity band and a year-by-year accumulation chart.
• FIRE Calculator — Find your FIRE number (annual expenses ÷ safe withdrawal rate — the 25× / 4% rule) and project the years, months and age to Financial Independence, Retire Early from your current savings, monthly investment and expected return, with a corpus-growth chart. Models Lean, Fat, Coast and Barista FIRE through your inputs.
• EMI Calculator — Equated monthly instalment, total interest and total cost for home, car and personal loans, with a full amortisation schedule and principal-vs-interest breakdown.
• Car Loan Calculator — Car loan monthly payment, total interest and total cost from the vehicle price, down payment and trade-in — with the financed amount, a full amortisation schedule and a principal-vs-interest breakdown.
• Amortization Calculator — Generic, US-style loan amortization: enter the loan amount, interest rate, term in years and payment frequency to get the payment per period, total interest, total paid and a full amortization schedule with a principal-vs-interest breakdown.
• Loan Payoff Calculator — Find your monthly payment, total interest, total cost and payoff time for any fixed-rate loan from the amount, rate and term — plus an optional extra monthly payment that shows exactly how much interest and time you save, with a full amortization schedule.
• Mortgage Refinance Calculator — Compare your current mortgage with a refinance offer: monthly savings, the break-even point on closing costs and your lifetime savings. Enter the balance, current and new rate, terms and closing costs to decide whether refinancing is worth it.
• Credit Card Payoff Calculator — See how long it takes to pay off a credit card at a fixed monthly payment, or the payment needed to be debt-free by a target date — with total interest, total cost and a full month-by-month payoff schedule.
• Home Loan Eligibility Calculator — Find out how much home loan you can get from your net monthly income, existing EMIs, FOIR, interest rate and tenure — with an optional LTV cap on the property value, your maximum affordable EMI and the binding constraint highlighted.
• Home Loan Prepayment Calculator — See how much interest a home loan prepayment saves. Model a one-time lumpsum or extra monthly part-payment, compare reduce-tenure vs reduce-EMI, and get the new payoff month, revised EMI, total interest before and after, and net interest saved.
• Personal Loan Eligibility Calculator — Find out how much personal loan you can get from your net monthly income, existing EMIs, FOIR, interest rate and tenure. See your maximum affordable EMI and the eligible loan amount, with a rate × tenure sensitivity table and a multiplier-method reference band.
• BMI Calculator — Body mass index from height and weight, with healthy-range guidance.
• BMR Calculator — Basal Metabolic Rate — the calories you burn at rest — from age, gender, height and weight, with TDEE by activity level and the Mifflin-St Jeor, Harris-Benedict and Katch-McArdle formulas.
• Pregnancy Calculator — Estimate your due date and gestational age from your last period, conception, IVF transfer or ultrasound, with your trimester, conception date and a 40-week milestone timeline.
• Body Fat Calculator — Estimate your body fat percentage with the U.S. Navy circumference method — from height, neck and waist (plus hip for women), with your ACE category and fat and lean mass, in metric or imperial.
• Water Intake Calculator — Find how much water to drink a day from your body weight and activity — your daily target in litres, millilitres and glasses, using 33 ml/kg plus 355 ml per 30 minutes of exercise. General guidance for healthy adults.
• Calorie Calculator — Daily calorie needs for weight loss, maintenance or muscle gain — with BMR, TDEE, macros, water intake and a personalised plan.
• Percentage Calculator — Work out what is X% of Y, what percent one number is of another, and the percentage increase or decrease between two values.
• LED Savings Calculator — Compare the annual electricity cost of an old incandescent, halogen or CFL bulb against an LED replacement — see the energy used in kWh and how much money you save per year and over 10 years, for one bulb or a whole house.
• Fraction Calculator — Add, subtract, multiply and divide fractions and get the answer in lowest terms, as a mixed number and as a decimal, with the working shown.
• Roman Numeral Converter — Convert numbers to Roman numerals and Roman numerals to numbers (1–3999), with a place-value breakdown, reference chart and validation.
• Age Calculator — Exact age in years, months and days from a date of birth, plus next-birthday countdown and total days lived.
• Age Difference Calculator — Compare two birth dates to see the exact age gap between two people, in years, months and days.
• Birthday Calculator — Fun birthday facts: zodiac sign, Chinese zodiac, the day of the week you were born, and your milestone birthday dates.
• Generation Calculator — Find which generation you belong to — Gen Z, Millennial, Gen X, Baby Boomer and more — from your birth year.
• CBSE Percentage Calculator — CBSE percentage calculator for Class 10 & 12: convert marks to percentage, CGPA to percentage (×9.5) and back, with subject-wise grades and best-of-five.
• SGPA to Percentage Calculator — Convert SGPA or CGPA to percentage with your university’s formula — VTU (SGPA − 0.75) × 10, direct × 10, CBSE × 9.5, Mumbai 7.1 × SGPA + 11, or a custom multiplier and offset.
• CGPA to Percentage Calculator — Convert CGPA to percentage with your board or university’s formula — CBSE/UGC × 9.5, generic × 10, VTU (CGPA − 0.75) × 10, Mumbai 7.1 × CGPA + 11, GTU × 8.8, or a custom multiplier.
• Percentage to CGPA Calculator — Convert percentage to CGPA with your board or university’s formula — CBSE/UGC ÷ 9.5, generic ÷ 10, VTU ÷ 10 + 0.75, Mumbai (Percentage − 11) ÷ 7.1, GTU ÷ 8.8, or a custom multiplier.
• Attendance Calculator — Calculate your attendance percentage and see how many classes you can bunk while staying above 75% — or how many you must attend to reach your target. Live both-sides formula with a what-if projection.
• Rent vs Buy Calculator — Compare the true net cost of renting vs buying over any horizon. Enter home price, mortgage details, ownership costs and rent, and see which path is cheaper, when buying breaks even, and the price-to-rent ratio for your market.
• Amps to Watts Calculator — Convert amperes to watts for DC, single-phase AC, and three-phase AC circuits using current, voltage, and power factor.
• Acceleration Calculator — Calculate acceleration from change in velocity over time, or from displacement and force — with instant unit-aware results in m/s².
• Air Fryer Conversion Calculator — Convert any conventional oven recipe to air fryer settings — lower temperature by 25 °F (15 °C) and reduce cooking time by up to 30%.
• Savings Goal Calculator — Find the required monthly (or periodic) deposit to reach a savings goal — from your target amount, starting balance, time horizon, and expected return rate.
• Annuity Calculator — Calculate the present value or future value of an annuity — a stream of equal periodic payments — for ordinary (end-of-period) or annuity-due (start-of-period) timing, at any payment frequency. Multi-currency.
• Break-Even Calculator — Find the break-even point in units and revenue for any product or business — from fixed costs, price per unit and variable cost per unit — with contribution margin and the target-profit variant.
• APR Calculator — Calculate the true annual percentage rate (APR) of any loan by factoring in fees alongside the interest rate — uses the actuarial IRR method required by Reg Z for accurate, fee-adjusted cost comparison.
• House Affordability Calculator — Find the maximum home price you can afford from your income, debts, down payment and rate — using the lender 28/36 DTI rule with full PITI accounting for taxes, insurance, HOA and PMI.
• Depreciation Calculator — Calculate asset depreciation with four standard accounting methods — straight-line, double-declining balance, sum-of-years-digits and units of production — with a year-by-year schedule.
• Present Value Calculator — Discount a future lump sum or a series of periodic payments back to today's money using the PV = FV / (1 + r)^n formula, with adjustable compounding frequency, optional annuity and a year-by-year discount table. Multi-currency.
• Net Worth Calculator — Calculate your personal net worth — total assets minus total liabilities — with a clear assets-vs-liabilities breakdown. Handles negative net worth, multi-currency.
• Student Loan Calculator — Monthly payment, total interest and total cost for any student loan — federal or private — from the loan amount, interest rate and repayment term, with a full amortisation schedule.
• VAT Calculator — Add VAT to a net price or remove it from a gross price — see the VAT amount and both the net and gross figures for any rate. Works for UK (20%), EU and global VAT rates.
• Roth IRA Calculator — Project your Roth IRA balance at retirement — tax-free — from your starting balance, annual contribution, current age, retirement age and expected return, with a year-by-year growth chart and a total contributions vs growth breakdown.
• Sales Tax Calculator — Calculate sales tax on any price — add tax to a net price or back-calculate the pre-tax amount from a tax-inclusive total. Works with any combined rate (state + county + city).
• Trading Expectancy Calculator — Calculate trading expectancy from win rate and average win/loss — the expected profit per trade in currency and R-multiples, over any number of trades.
• Profit Factor Calculator — Calculate profit factor — gross profit divided by gross loss — from your win rate and average win and loss, to see how many dollars you make per dollar lost.
• SQN Calculator (System Quality Number) — Calculate Van Tharp's System Quality Number (SQN) from win rate, average win/loss and trade count to score how strong and reliable your trading system is.
• Trading Edge Calculator — Measure your trading edge — expected profit per unit risked (edge in R) — from win rate and average win/loss, with your breakeven win rate and Kelly stake.
• Risk of Ruin Calculator — Calculate your risk of ruin — the chance of hitting a drawdown threshold — from win rate, average win/loss and risk per trade, using the classic formula.
• Fixed Fractional Position Size Calculator — Fixed-fractional position sizing: risk a constant fraction of equity per trade. Enter account, f %, entry and stop to get share count, max loss and capital required.
• Volatility (ATR) Position Size Calculator — Size any trade by volatility: enter account size, risk %, ATR and ATR multiple to get the exact share count, max loss, risk per share and capital required.
• Kelly Criterion Calculator — Calculate your optimal Kelly bet size — the mathematically proven fraction of your bankroll to risk per trade, based on win rate, average win/loss, and account size.
• Pyramiding Calculator — Calculate your blended average entry, total capital, total risk and constant-risk stop when scaling into a winning position across multiple tranches.
• Multi-Leg Average Entry Calculator — Blended quantity-weighted entry across options legs, futures rolls and staged tranches. Enter each leg's price and quantity for your average entry and P&L.
• Scale In / Scale Out Calculator — Blend buy lots into one average entry, then model a partial exit: realized P&L, remaining shares, remaining cost basis and unrealized P&L on what you still hold.
• Portfolio Heat Calculator — Calculate total portfolio heat — the percentage of account equity at risk if every open position hits its stop simultaneously. Based on Elder's 6% rule.
• Drawdown Recovery Calculator — Calculate the gain needed to recover from a portfolio drawdown and how long recovery takes at a given return rate.
• Stop-Loss Calculator — Calculate your stop-loss price by percentage, fixed dollar, or ATR method — plus risk per share and total position risk for long or short trades.
• Probability of Profit Calculator — Estimate the risk-neutral probability that an options trade finishes on the profitable side of its breakeven at expiration using the Black-Scholes lognormal model.
• Liquidation Price Calculator — Estimate the forced-liquidation mark price for an isolated-margin USDT-margined futures position given entry price, leverage, side and maintenance margin rate.
• Slippage & Commission Calculator — Calculate real execution costs — slippage, broker commission (%, per-share or flat), round-trip total and the break-even move required to cover all trading costs.
• Black-Scholes Calculator — Price European call and put options with the Black-Scholes-Merton model and get the full Greeks — Delta, Gamma, Vega, Theta and Rho — from six inputs.
• Trailing Stop Calculator — Find the trailing stop price for a long or short position from your water mark and a percentage or fixed trail, plus the distance to trigger.
• Trading Margin Calculator — Work out the required margin for a leveraged forex, stock or crypto position from its size and leverage, plus free margin and margin level.
• Options Greeks Calculator — Black-Scholes option price and all five Greeks — Delta, Gamma, Vega, Theta, Rho — for European calls and puts, with dividend yield for equity and index options.
• Absence Percentage Calculator — Calculate absence rate and attendance percentage from days (or hours) absent and total scheduled days — the standard HR and school absenteeism formula.
• ARM Mortgage Calculator — Project adjustable-rate mortgage payments through every rate phase. Enter the index, margin and caps to see your payment after each adjustment and a full schedule.
• Biweekly Mortgage Calculator — See how biweekly mortgage payments cut years off your loan. Enter your balance, rate and term to get the payoff date and interest saved vs a monthly schedule.
• Interest-Only Mortgage Calculator — See your interest-only payment, the higher principal-and-interest payment after the IO period ends, total interest, and a full two-phase schedule.
• Land Loan Payment Calculator — Monthly payment, total interest and total cost of a land or lot loan from the price, down payment, rate and term — with a full amortization schedule.
• Mortgage Calculator with Taxes and Insurance — Calculate your true monthly PITI mortgage payment: principal, interest, property taxes, homeowner's insurance and PMI, with a full payment breakdown.
• Mortgage Comparison Calculator — Compare two mortgage offers side by side — monthly payment, total interest and total cost for each — and see which loan saves more money over its term.
• Mortgage Payoff Calculator — See your full mortgage cost — PITI payment, amortization schedule, and how extra, lump-sum, or biweekly payments shorten your payoff and cut total interest.
• Savings Plan Calculator — Project how much your savings will grow from regular deposits at a chosen interest rate — see final balance, total contributed and interest earned.
• Weight Loss Percentage Calculator — Calculate the percentage of body weight lost from your starting weight, plus how much more to lose to reach your goal.
• Breastfeeding Calorie Calculator — Estimate daily calories while breastfeeding — Mifflin-St Jeor BMR × activity plus a lactation add-on (500 kcal exclusive, 330 partial), per CDC and FAO.
• E20 Mileage Impact Calculator — See how much mileage you lose and the extra fuel cost per month and year on E20 petrol — from your car's km/L, monthly distance and pump price.
• Fuel Cost per km Comparator — Compare your real running cost per km across petrol, E20 (ethanol blend), CNG and EV — see which fuel saves you the most money every month.
• Ethanol Blend Calculator — Find the ethanol and petrol volumes in any E-blend (E5, E10, E20, E85) and see the theoretical energy content compared to pure petrol.
• Final Grade Calculator — Find out what score you need on your final exam to achieve your target course grade — instantly solves the weighted-grade equation for any final exam weight.
• Semester Grade Calculator — Calculate your weighted semester grade from assignment, quiz, midterm and final scores — plus find out what you need on the final exam to hit your target grade.

More calculators are on the way. Have a request? Tell us.

A note on accuracy

Our calculators are provided for general information and illustration only. They are not financial, medical, legal or tax advice. Always confirm important decisions with a qualified professional. See our Terms for details.