Free online calculators & converters
KiraCalc is a free collection of fast, accurate online calculators and unit converters — dates, percentages, health, money and everyday math. No sign-up, works on any device.
Date & Time
Ages, date differences, countdowns and working days.
Age Calculator
Find your exact age in years, months and days from your date of birth.
Date Difference Calculator
Count the number of days, weeks and months between two dates.
Date Calculator: Add or Subtract Days
Add or subtract any number of days from a date to find the resulting date.
Countdown Calculator: Days Until a Date
Count down the days until any future date or event.
Working Days Calculator
Count the working days (Monday–Friday) between two dates.
Math & Percentages
Percentages, averages, ratios and fractions.
Percentage Calculator
Work out X% of a number, what percent one number is of another, and percentage change.
Average (Mean) Calculator
Find the mean, median, sum, minimum and maximum of a list of numbers.
Ratio Calculator
Simplify a ratio and scale it up or down to find an equivalent ratio.
Fraction to Decimal Calculator
Convert fractions to decimals and decimals back to simplified fractions.
Health & Fitness
BMI, calories and ideal weight, using standard formulas.
Everyday Money
Tips, discounts, loan payments and fuel costs.
Tip Calculator
Work out the tip and split the bill between any number of people.
Discount Calculator
Find the sale price and how much you save from a percentage discount.
Loan Payment Calculator
Estimate the monthly payment, total cost and interest on a loan.
Fuel Cost Calculator
Estimate the fuel needed and the cost of a trip.
Unit Converters
Length, weight, temperature and cooking conversions.
Length Converter
Convert between millimetres, centimetres, metres, kilometres, inches, feet, yards and miles.
Weight Converter
Convert between grams, kilograms, tonnes, ounces, pounds and stone.
Temperature Converter
Convert between Celsius, Fahrenheit and Kelvin.
Cooking Measurement Converter
Convert between millilitres, litres, teaspoons, tablespoons, cups and more.
Popular instant answers
Quick, ready-made calculations people look up most.