Convert. Calculate. Understand.

Free converters and calculators that show their working, so you can trust the answer.

Formula shown every timeFree, no sign-upWorks on phone and desktop

Converters Money Health Home & DIY Everyday

Salary Calculator— Tax, net pay & take-home pay by country

Popular right now

The tools most people use every day.

Currency

Daily ECB exchange rates

Length

Inches, feet, centimeters

BMI Calculator

With WHO category labels

Mortgage Calculator

Monthly payment & total interest

Percentage Calculator

% of, is what % of & % change

Tip Calculator

Split bills, custom percentages

Temperature

Celsius, Fahrenheit, Kelvin

Loan Calculator

Monthly payments for any loan

Weight & Mass

kg, lbs, stone, oz, metric ton & more

Age Calculator

Years, months & days between dates

Compound Interest

Savings growth over time

Calorie Burn

By activity, duration & weight

Unit converters

Length, weight, temperature, volume, speed, area and more.

Distance

Miles, kilometers, meters & more

Currency

Daily ECB exchange rates

Time

Hours, minutes, seconds, days

Time Zones

Convert between time zones

Temperature

Celsius, Fahrenheit, Kelvin

Speed

MPH, KPH, knots & more

Weight & Mass

kg, lbs, stone, oz, metric ton & more

Length

Inches, feet, centimeters

Liquid Volume

Liters, gallons, ounces

Area

sq ft, sq m, acres, hectares

Pressure

PSI, bar, Pascal, atm, mmHg

Energy

Joules, kcal, kWh, BTU

Data Storage

GB, TB, GiB — decimal vs binary

Angle

Degrees, radians, gradians

Fuel Efficiency

MPG, L/100km, km/L

Height

cm ↔ feet & inches ↔ meters

Shoe Size

US, UK, EU, cm + brand variants

Baking

Cups, tbsp, grams & oz for recipes

Tire Size & Speedo

Compare tire sizes & speedometer error

Road Trip Fuel Cost

Split trip fuel between passengers

Pan Size Scaler

Scale recipes to any pan size

Sourdough Hydration

Bakers percentage for your dough

Money & finance

Loans, mortgages, interest, tax, salary and currency.

Tip Calculator

Split bills, custom percentages

Loan Calculator

Monthly payments for any loan

Compound Interest

Savings growth over time

VAT / GST Calculator

Add or remove tax from a price

Salary Converter

Hourly → daily → weekly → annual

Salary Calculator

Tax, net pay & social security by country

Digital Nomad Visa Guide

16 countries: income, duration & tax

Discount Calculator

What is 30% off £45?

Debt Payoff

Snowball vs avalanche strategy

Inflation / CPI

See what money was worth over time

Amortization Schedule

Full loan payment breakdown

Retirement / 401(k)

Contributions, match & growth

Mortgage Calculator

Monthly payment & total interest

Auto Loan

Car finance payment & interest

Sales Tax

Add or remove sales tax

Simple Interest

Interest on the principal only

Credit Card Payoff

Payoff time, interest & targets

Health & fitness

BMI, calories, body measurements and training zones.

BMI Calculator

With WHO category labels

Calorie Burn

By activity, duration & weight

Running Pace

min/km ↔ min/mile ↔ mph ↔ km/h

Macro Calculator

Protein, carbs & fat from calories

Blood Pressure

Interpret your mmHg reading

TDEE Calculator

Daily calorie burn from BMR & activity

Body Fat %

Navy method body fat estimate

Pet Food Calories

Daily calories for dogs & cats

Ideal Weight

Devine, Robinson, Miller & Hamwi

Healthy Weight

WHO BMI range for your height

Pregnancy Weight Gain

IOM guidelines by week & BMI

Due Date

From last period or conception

Ovulation

Ovulation day & fertile window

Period Tracker

Next periods & fertile windows

Kidney Function (GFR)

eGFR from creatinine (CKD-EPI 2021)

Body Type

Shape from bust, waist & hips

Body Surface Area

Mosteller, Du Bois & more in m²

BAC

Blood alcohol (Widmark estimate)

Army Body Fat

US Army tape method

One Rep Max

Estimate 1RM from any set

Target Heart Rate

Karvonen training zones

WW Points (Classic)

Legacy points from a food label

Home & DIY

How much paint, tile, concrete or flooring to buy.

Paint Coverage

Room dimensions → litres needed

Tile Calculator

Area + tile size → quantity + waste

Concrete Volume

Dimensions → m³ + bags of mix

Wallpaper Calculator

Room dimensions → number of rolls

Flooring Calculator

Area + wastage → material needed

Deck / Lumber

Boards, joists & linear feet

Everyday calculators

Percentages, dates, averages, time zones and more.

Percentage Increase / Decrease

How much a value went up or down

Growth Rate

Map growth over time

Average & Median

Statistical calculations

Distance Between Cities

Great-circle distance worldwide

Days Calculator Between Two Dates

Days, months & years between dates

Age Calculator

Years, months & days between dates

Roman Numerals

Convert numbers to and from Roman

TV Viewing Distance

How far to sit from your screen

Coffee Ratio

Coffee-to-water ratio by method

Percentage Calculator

% of, is what % of & % change

Standard Deviation

Mean, variance & spread of data

Volume Calculator

Box, cylinder, sphere, cone & pyramid

Sleep Calculator

Bedtime & wake-up by sleep cycles

Day of the Week

Weekday for any date

Convert & Calculate is a set of free tools for everyday numbers. Each one shows how the answer is worked out, uses standard definitions (an inch is exactly 2.54 cm, for example) and explains what your result means. There is nothing to install and no account to create.