New Calculators

Convert a height in centimetres to feet and inches with exact international conversion factors.

Convert length between metric and imperial units — millimetres, centimetres, metres, kilometres, inches, feet, yards, miles, and nautical miles.

Work out how many litres of paint you need from your wall area, the number of coats, and the paint's coverage per litre.

Work out your new pay and the size of the increase from a raise percentage — currency-agnostic, works for hourly or annual pay, and handles pay cuts too.

Calculate the percentage increase or decrease between an original value and a new value, with the absolute difference shown alongside.

Convert power between metric, imperial, and thermal units — watts, kilowatts, megawatts, mechanical horsepower, metric horsepower (PS), and BTU per hour.

Calculate the pixel density (PPI) and dot pitch of any display from its pixel resolution and physical diagonal in inches.

Discount a future lump sum and any regular future payments back to today's money, with the discount applied and the nominal total, at monthly, quarterly, or annual compounding.

Solve a proportion A : B = C : D for the missing value and reduce the ratio A : B to its simplest whole-number form.

Estimate how long a text takes to read from its word count and your reading speed, shown in minutes and seconds.

Scale any recipe up or down — enter an ingredient amount and your original and desired servings to get the rescaled amount and the scaling factor.

Estimate how many years it takes for money to double, triple, or quadruple at a fixed annual rate, and compare the Rule of 72 shortcut with the exact doubling time.

Solve for the unknown value in a proportion using the rule of three (Dreisatz), with support for both direct and inverse relationships.

Convert shoe sizes between EU, UK, US (Men), US (Women), and foot length in centimetres — instantly, using the documented foot-length method.

Convert speed between metric, imperial, and nautical units — metres per second, kilometres per hour, miles per hour, feet per second, and knots.

Convert temperature between Celsius, Fahrenheit, and Kelvin — instantly and with exact, offset-based scale definitions.

Calculate your test grade as a percentage and a US A–F letter grade from the points you earned out of the total possible points.

Work out how many tiles you need to cover a floor area, including a waste allowance for cuts and breakages.

Find out how long to roast a turkey at 325°F — enter the weight and whether it is stuffed to get the total roasting time in hours and minutes.

Convert volume between metric, US customary, and UK imperial units — millilitres, centilitres, litres, cubic metres, US teaspoons, tablespoons, fluid ounces, cups, pints, quarts, US gallons, and UK gallons.

Work out how many rolls of wallpaper you need to cover a wall area, including a waste allowance for pattern matching and trimming.

Convert weight (mass) between metric and imperial units — milligrams, grams, kilograms, metric tonnes, ounces, pounds, and stone.

Estimate your body fat percentage using the US Navy circumference method.

Calculate your exact age in years, months, and days from your date of birth. Find your total days lived and days until your next birthday.

Calculate your Basal Metabolic Rate using the Mifflin-St Jeor, Harris-Benedict, or Katch-McArdle equation — plus your activity-adjusted daily calorie needs.

Find out exactly what you need on your final exam to hit your target course grade. Enter your current grade, desired grade, and the final's weight.

Calculate trip fuel cost and split by passenger. Supports l/100km, mpg US, mpg UK, and km/l.

Solve any one of pace, time, or distance from the other two. Plan your race or training run.

Calculate percentages in three modes: find a percentage of a number, find what percent one number is of another, or calculate percentage change between two values.

Convert any gross pay amount between pay periods — hourly, daily, weekly, biweekly, monthly, or annual. See all equivalent rates instantly.

Calculate the exact tip amount, total bill, and per-person split instantly.

Add VAT to a net amount or extract VAT from a gross amount. Covers statutory rates for Germany (19 %, 7 %), Austria (20 %, 10 %, 13 %), and Switzerland (8.1 %, 2.6 %, 3.8 %) plus a custom rate.

Calculate the percent error between a measured value and the accepted (true) value, plus the absolute error.

Calculate your waist-to-hip ratio (WHR) and see your cardiometabolic risk band using the WHO 2008 cut-offs.

Estimate mowing productivity in acres per hour from your cutting width, ground speed, and efficiency — plus hours per acre and time to finish an area.

Calculate your ACT composite score from the four section scores (English, Math, Reading, Science) and see the national percentile rank.

See how much interest and how many months you save on a car loan by adding an extra payment each month.

Estimate the calories you burn cycling using the MET method, from your body weight, riding speed, and ride length — plus the distance covered and the MET intensity.

See your biweekly mortgage payment and how much interest and time you save versus a standard monthly schedule, from the loan amount, rate, and term.

Calculate the balance-weighted blended interest rate across two or three loans, plus the total balance and annual interest.

Estimate the cost of a short-term, interest-only bridge loan: the monthly interest payment, total interest, origination fee, and total cost.

Estimate the interest-only payment during the build, total construction-phase interest, and the permanent mortgage payment for a construction-to-permanent loan.

Calculate the cost of equity with the CAPM formula from the risk-free rate, beta, and expected market return — plus the equity risk premium.

Work out how much concentrate and water to mix for a given dilution ratio like 1:10, for any target volume.

Estimate a vehicle's diminished value after accident repair using the insurance industry's 17c formula.

Calculate the point-buy cost of your six D&D 5e ability scores against the 27-point budget, with points spent and remaining and instant validity checking.

Work out your dog's due date and whelping window from the breeding date — canine gestation averages 63 days, with a normal range of 58 to 68 days.

Score a fantasy football stat line under standard, half-PPR, or full-PPR rules, with a breakdown of passing, rushing, and receiving points.

Estimate total body water and the free water deficit used to correct hypernatremia, from weight, patient group, and serum sodium.

Project the future value of a starting amount plus regular contributions, with the interest earned and total paid in, at monthly, quarterly, or annual compounding.