Free Online Calculators for Everyday Life

Calculate your exact age in years, months, and days from your date of birth. Also shows total days lived and a countdown to your next birthday.

Count the days, weeks, months, and years between any two dates. Perfect for deadlines, anniversaries, project timelines, and countdowns.

Work out percentages instantly: what is X% of Y, X is what percent of Y, and percentage increase or decrease between two numbers.

Calculate your Body Mass Index from height and weight in metric or imperial units, see your WHO weight category, and the healthy weight range for your height.

Work out the tip and total for any bill, split it between any number of people, and round the total up or down to a clean amount.

Find the sale price and money saved from a percentage discount, stack a second discount, and see the effective total percentage off.

Calculate the monthly payment, total interest, and total cost of a loan or mortgage from the amount, annual interest rate, and term.

See how savings or investments grow over time with compound interest and optional regular contributions, at any compounding frequency.

Estimate your daily calorie needs (TDEE) from age, sex, height, weight, and activity level using the Mifflin-St Jeor equation, with targets for losing or gaining weight.

Add sales tax to a price to get the tax amount and total, or work backwards from a tax-inclusive total to find the pre-tax price and tax paid.

Convert pay between hourly, daily, weekly, monthly, and annual amounts based on your hours per week and weeks worked per year.

Calculate your weighted grade point average on a 4.0 scale from your course grades and credit hours, with each course counted by its weight.

Estimate your pregnancy due date from your last menstrual period using Naegele’s rule, adjusted for your cycle length, plus how many weeks along you are.

Work out the time between a start and end time, subtract an unpaid break, and get the duration in hours and minutes and as a decimal for timesheets.

Calculate your running pace per kilometre or mile from distance and time, and see your average speed for training and race planning.

Convert temperatures instantly between Celsius, Fahrenheit, and Kelvin, with the exact conversion formulas shown for each pair.

Estimate your ideal body weight from height and sex using the Robinson, Devine, Miller, and Hamwi formulas, plus the healthy weight range for your height.

Estimate your body fat percentage with the U.S. Navy method from a few tape measurements, and see your body fat category and fat mass.

Calculate return on investment as a percentage from your cost and final value, plus the annualized return when you enter a holding period.

Work out the fuel cost of a trip from the distance, your vehicle’s fuel economy, and the price of fuel, in metric or imperial units.

Estimate your full monthly mortgage payment from the home price, down payment, interest rate, and term — including property tax and home insurance.

Find out how much you need to save each month to reach a savings goal by a target date, taking your starting balance and interest into account.

Convert lengths and distances between millimetres, centimetres, metres, kilometres, inches, feet, yards, and miles instantly.

Estimate your most fertile days, ovulation date, and next period from the first day of your last period and your average cycle length.

Convert weight and mass between milligrams, grams, kilograms, ounces, pounds, and stones instantly, with every unit shown at once.

Estimate the calories you burn during exercise from your body weight, the activity, and how long you do it, using MET values.

Calculate simple interest and the total amount from a principal, annual interest rate, and time period, with the exact formula shown.

Work out selling price, profit, and profit margin from a cost and a markup percentage — and see the difference between markup and margin.

Convert speed between kilometres per hour, miles per hour, metres per second, feet per second, and knots instantly.

Calculate brokerage commission, day-trade transaction tax, and the exact breakeven price for a Taiwan Stock Exchange (TWSE) day trade, including broker discounts and minimum fees.