Calculators that show their work
Most calculators hand you a number and stop. These give you the formula, the month-by-month breakdown, and the assumptions behind the result - so you can check the answer rather than trust it.
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Most used
- Mortgage CalculatorEstimate your monthly mortgage payment - including taxes, insurance, and PMI - and see exactly how much interest you'll pay over the life of the loan.Open
- BMI CalculatorCalculate your body mass index in metric or imperial units, and see where it falls on the standard scale.Open
- Percentage CalculatorSolve every common percentage question - what is X% of Y, X is what percent of Y, and the percentage change between two numbers.Open
- Loan CalculatorCalculate the monthly payment, total interest, and payoff date on any fixed-rate loan - then see the full schedule behind the number.Open
- Calorie CalculatorFind your daily calorie needs from your BMR and activity level, with targets for losing, maintaining, or gaining weight.Open
- Age CalculatorWork out an exact age in years, months, and days from any date of birth - plus total days lived and the countdown to the next birthday.Open
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81 calculators match
Finance
View all- Mortgage CalculatorEstimate your monthly mortgage payment - including taxes, insurance, and PMI - and see exactly how much interest you'll pay over the life of the loan.
- Loan CalculatorCalculate the monthly payment, total interest, and payoff date on any fixed-rate loan - then see the full schedule behind the number.
- Auto Loan CalculatorWork out your real monthly car payment with sales tax, trade-in value, and fees included - not just the sticker price.
- Amortization CalculatorGenerate a complete payment-by-payment schedule for any loan, and see exactly how each payment splits between principal and interest.
- Paycheck CalculatorSee your real take-home pay after federal tax, Social Security, Medicare, state tax, and retirement contributions - for 2026.
- Compound Interest CalculatorSee how savings grow when interest earns interest - with monthly contributions and a year-by-year breakdown of the balance.
- Retirement CalculatorProject what your 401(k) and savings will be worth at retirement, and see how long that balance actually lasts.
- Credit Card Payoff CalculatorFind out how long your credit card balance takes to clear, what the interest costs, and how much faster a bigger payment gets you there.
- Home Affordability CalculatorFind the home price your income actually supports, using the debt-to-income limits lenders apply - and see which limit is binding.
- UK Take-Home Pay CalculatorSee exactly what lands in your bank account each month after income tax, National Insurance, pension and student loan - for England, Wales, Northern Ireland and Scotland.
- Canada Take-Home Pay CalculatorCalculate your net pay after federal tax, provincial tax, CPP and EI - for every province and territory, including Quebec’s separate QPP.
- Australia Take-Home Pay CalculatorWork out your net pay after income tax, the Medicare levy and HECS-HELP - and see whether a salary quoted "including super" is really the better offer.
- Refinance CalculatorSee whether refinancing actually saves you money - the monthly saving, the break-even month, and whether a lower payment is quietly costing you more.
- Debt Payoff CalculatorCompare the snowball and avalanche methods across all your debts at once - see which clears first, what each costs in interest, and when you are free.
- Down Payment CalculatorWork out the cash you need to buy - down payment, closing costs, and how long saving will take - plus what PMI costs at each threshold.
- Savings Goal CalculatorFind out exactly how much to put aside each month to hit a target by a date - and how long your current contribution would actually take.
- ROI CalculatorCalculate return on investment and, more usefully, the annualised return that lets you compare one investment against another.
- Inflation CalculatorSee what money is really worth over time - how much you would need in future to buy what a sum buys today, and how fast purchasing power erodes.
- Salary CalculatorConvert between hourly pay and an annual salary in either direction, with overtime and unpaid weeks accounted for properly.
Health
View all- BMI CalculatorCalculate your body mass index in metric or imperial units, and see where it falls on the standard scale.
- Calorie CalculatorFind your daily calorie needs from your BMR and activity level, with targets for losing, maintaining, or gaining weight.
- Due Date CalculatorEstimate your due date from your last period, conception date, or a known due date - and see exactly how far along you are.
- BMR CalculatorFind the calories your body burns at rest and across your whole day, with daily targets for losing, maintaining or gaining weight.
- Body Fat CalculatorEstimate your body fat percentage from tape measurements using the US Navy method, with lean mass and healthy ranges by sex.
Everyday
View all- Percentage CalculatorSolve every common percentage question - what is X% of Y, X is what percent of Y, and the percentage change between two numbers.
- Age CalculatorWork out an exact age in years, months, and days from any date of birth - plus total days lived and the countdown to the next birthday.
- Tip CalculatorCalculate the tip and split the check between any number of people, with a rounding option and a US tipping reference.
- Time Zone ConverterConvert a time across cities and plan meetings that land in working hours everywhere - with daylight saving handled automatically.
- Date CalculatorCount the days, weeks and business days between two dates, or add and subtract time from any date to find the result.
- GPA CalculatorCalculate your semester and cumulative grade point average, weighted by credit hours, with support for honors and AP courses.
- Grade CalculatorWork out your current weighted grade and exactly what you need on the final exam to finish with the grade you are aiming for.
- Pace CalculatorConvert between pace, distance and finish time for any race, with splits and predicted times at every standard distance.
Converters
View all- CM to Inches ConverterConvert centimeters to inches instantly, with a reference table for the sizes you look up most.
- KG to LBS ConverterConvert kilograms to pounds instantly, with a reference table covering everyday body and package weights.
- Celsius to Fahrenheit ConverterConvert °C to °F instantly, with a reference table covering weather, body temperature, and cooking.
- MM to Inches ConverterConvert millimeters to inches instantly, with a reference table for common hardware and screen sizes.
- KM to Miles ConverterConvert kilometers to miles instantly, with a reference table covering race distances and road trips.
- Meters to Feet ConverterConvert meters to feet instantly, with a reference table for heights, rooms, and elevations.
- Ounces to Grams ConverterConvert ounces to grams instantly, with a reference table sized for recipes and postage.
- MPH to KM/H ConverterConvert miles per hour to kilometers per hour instantly, with a reference table of common speed limits.
- Inches to CM ConverterConvert inches to centimeters instantly, with a reference table covering screen sizes, waist measurements and hardware dimensions.
- Feet to Meters ConverterConvert feet to meters instantly, with a reference table covering room dimensions, heights and altitudes.
- Miles to KM ConverterConvert miles to kilometers instantly, with a reference table covering race distances, speed limits and journey lengths.
- Feet to Inches ConverterConvert feet to inches instantly, with a reference table for heights, lumber lengths and room dimensions.
- CM to Feet ConverterConvert centimeters to feet instantly, with a reference table covering the heights people look up most.
- Meters to Yards ConverterConvert meters to yards instantly, with a reference table covering track distances, fabric lengths and sports fields.
- Inches to MM ConverterConvert inches to millimeters instantly, with a reference table covering drill sizes, fasteners and fractional inches.
- Yards to Meters ConverterConvert yards to meters instantly, with a reference table covering fabric, sports fields and golf distances.
- KM to Meters ConverterConvert kilometers to meters instantly, with a reference table for race distances, altitudes and map scales.
- LBS to KG ConverterConvert pounds to kilograms instantly, with a reference table covering body weight, luggage limits and gym plates.
- Grams to Ounces ConverterConvert grams to ounces instantly, with a reference table covering recipe quantities and postal weights.
- KG to Stone ConverterConvert kilograms to stone instantly, with a reference table covering the body weights UK scales report.
- Stone to LBS ConverterConvert stone to pounds instantly, with a reference table for translating UK body weights into American terms.
- Grams to LBS ConverterConvert grams to pounds instantly, with a reference table covering package weights and bulk quantities.
- Ounces to LBS ConverterConvert ounces to pounds instantly, with a reference table for shipping weights, groceries and infant weights.
- Liters to Gallons ConverterConvert liters to US gallons instantly, with a reference table for fuel, tanks and bulk liquids.
- Gallons to Liters ConverterConvert US gallons to liters instantly, with a reference table for fuel tanks, aquariums and paint.
- ML to Ounces ConverterConvert milliliters to US fluid ounces instantly, with a reference table for drinks, bottles and cabin liquid limits.
- Ounces to ML ConverterConvert US fluid ounces to milliliters instantly, with a reference table for cocktails, baby bottles and drink sizes.
- Cups to ML ConverterConvert US cups to milliliters instantly, with a reference table for baking and the cup sizes other countries use.
- ML to Cups ConverterConvert milliliters to US cups instantly, with a reference table for turning metric recipes into American measures.
- Tablespoons to ML ConverterConvert tablespoons to milliliters instantly, with a reference table and the tablespoon sizes used outside the US.
- Teaspoons to ML ConverterConvert teaspoons to milliliters instantly, with a reference table for recipes and liquid medicine doses.
- Quarts to Liters ConverterConvert US quarts to liters instantly, with a reference table for stockpots, motor oil and food storage.
- Pints to ML ConverterConvert US pints to milliliters instantly, and see how the American pint compares with the imperial one.
- Liters to ML ConverterConvert liters to milliliters instantly, with a reference table for bottles, doses and container sizes.
- Fahrenheit to Celsius ConverterConvert °F to °C instantly, with a reference table covering weather, fever thresholds and oven temperatures.
- Celsius to Kelvin ConverterConvert Celsius to kelvin instantly, with a reference table covering absolute zero, everyday temperatures and lab conditions.
- Kelvin to Celsius ConverterConvert kelvin to Celsius instantly, with a reference table covering cryogenics, light colour temperature and stellar surfaces.
- Square Feet to Square Meters ConverterConvert square feet to square meters instantly, with a reference table covering rooms, apartments and houses.
- Square Meters to Square Feet ConverterConvert square meters to square feet instantly, with a reference table for flooring, listings and land.
- Acres to Hectares ConverterConvert acres to hectares instantly, with a reference table covering farmland, plots and estates.
- Hectares to Acres ConverterConvert hectares to acres instantly, with a reference table for farmland, forestry and land listings.
- KMH to MPH ConverterConvert kilometers per hour to miles per hour instantly, with a reference table of speed limits worldwide.
- Knots to MPH ConverterConvert knots to miles per hour instantly, with a reference table covering wind speeds, aircraft and vessels.
- KJ to Calories ConverterConvert kilojoules to food calories instantly, with a reference table for nutrition labels and daily intake.
- Calories to KJ ConverterConvert food calories to kilojoules instantly, with a reference table for exercise, meals and daily targets.
- Watts to Horsepower ConverterConvert watts to mechanical horsepower instantly, with a reference table covering engines, motors and appliances.
- Horsepower to Watts ConverterConvert horsepower to watts instantly, with a reference table for engines, EV motors and power tools.
- PSI to Bar ConverterConvert psi to bar instantly, with a reference table covering tyre pressures, espresso machines and compressors.
- Bar to PSI ConverterConvert bar to psi instantly, with a reference table for tyres, diving cylinders and pressure washers.