TheCalculatorHive™

Math & Everyday Calculators

12 tools

Percentages, dates, ages and everyday math.

Percentages

PercentageWork out what is X% of Y, what percent one number is of another, and the percentage increase or decrease between two values.Absence %Calculate absence rate and attendance percentage from days (or hours) absent and total scheduled days — the standard HR and school absenteeism formula.

Energy

LED SavingsCompare 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.

Fractions

FractionAdd, subtract, multiply and divide fractions and get the answer in lowest terms, as a mixed number and as a decimal, with the working shown.

Conversions

Roman NumeralConvert numbers to Roman numerals and Roman numerals to numbers (1–3999), with a place-value breakdown, reference chart and validation.

Dates & Age

AgeExact age in years, months and days from a date of birth, plus next-birthday countdown and total days lived.Age DifferenceCompare two birth dates to see the exact age gap between two people, in years, months and days.BirthdayFun birthday facts: zodiac sign, Chinese zodiac, the day of the week you were born, and your milestone birthday dates.GenerationFind which generation you belong to — Gen Z, Millennial, Gen X, Baby Boomer and more — from your birth year.

Electrical

Amps to WattsConvert amperes to watts for DC, single-phase AC, and three-phase AC circuits using current, voltage, and power factor.

Physics

AccelerationCalculate acceleration from change in velocity over time, or from displacement and force — with instant unit-aware results in m/s².

Cooking

Air FryerConvert any conventional oven recipe to air fryer settings — lower temperature by 25 °F (15 °C) and reduce cooking time by up to 30%.