Free online calculators
Simple, fast calculators for money, maths, health, building, travel, weather, electronics and everyday life. Everything runs in your browser, with no sign-up.
Financial
Salary calculator
UK take-home pay with tax code, student loan, pension and more.
Income tax calculator
UK income tax and National Insurance for 2026/27.
Mortgage calculator
Monthly payment, total interest and loan to value.
Loan calculator
Monthly payment and total interest on any loan.
Car loan calculator
Monthly payment for a car, with deposit.
Interest rate calculator
Find the interest rate from a loan and payment.
Amortisation calculator
Year by year loan schedule showing interest and balance.
Compound interest calculator
Watch savings grow with interest and monthly additions.
Simple interest calculator
Interest on an amount over a number of years.
Retirement calculator
Estimate your pension pot and monthly income.
Inflation calculator
What prices and money are worth after years of inflation.
VAT calculator
Add or remove VAT from any price.
Sales tax calculator
Add or remove sales tax at any rate.
Tip calculator
Split the bill and work out the tip.
Discount calculator
Sale price and how much you save.
Math
Scientific calculator
Trig, logs, powers, roots and brackets.
Percentage calculator
Percent of a number, percent change, increase or decrease.
Percentage change calculator
Percent increase or decrease between two numbers.
Average calculator
Mean, median, mode and range of a list.
Standard deviation calculator
Standard deviation, variance and mean.
Fraction calculator
Add, subtract, multiply and divide fractions.
Triangle calculator
Area, perimeter and angles from three sides.
Random number generator
Pick random numbers in any range.
Fitness & Health
BMI calculator
Body mass index and a healthy weight range.
Calorie calculator
Daily calories to maintain, lose or gain weight.
BMR calculator
Calories your body burns at rest.
Body fat calculator
Estimate body fat with a tape measure.
Ideal weight calculator
Target weight from four classic formulas.
Pace calculator
Running pace per mile and per kilometre.
Pregnancy due date calculator
Estimated due date from your last period.
Child height predictor
Predict a child's adult height from the parents.
Date & Time
Age calculator
Exact age in years, months and days.
Date calculator
Days between dates, or add days to a date.
Time calculator
Add or subtract days, hours, minutes and seconds.
Hours calculator
Hours worked between two times, with breaks and pay.
Day of the week calculator
Which day of the week any date falls on.
Time zone converter
Convert a time between cities and time zones.
Sleep calculator
Best bedtimes and wake-up times from sleep cycles.
Home & Building
Concrete calculator
Volume and bags of concrete for a slab.
Square footage calculator
Area of a room, plot or shape in any unit.
Stair calculator
Steps, riser height and stringer length for a staircase.
Roofing calculator
Roof area, squares and shingle bundles from pitch.
Tile calculator
How many tiles and boxes you need for a floor or wall.
Mulch calculator
Cubic yards, metres and bags of mulch for a bed.
Gravel calculator
Volume and weight of gravel, stone or sand.
BTU calculator
Air conditioner size for a room.
Travel & Cars
Fuel cost calculator
Cost of a journey from distance and mpg.
Speed distance time calculator
Find speed, distance or time.
Gas mileage calculator
Miles per gallon, litres per 100 km and more.
Horsepower calculator
Horsepower from torque, or from quarter-mile time.
Mileage allowance calculator
Business mileage claim at HMRC or custom rates.
Tyre size calculator
Compare two tyre sizes and speedometer error.
Science & Weather
Unit converter
Length, weight, volume, area, speed, temperature and time.
Density calculator
Density, mass or volume from the other two.
Roman numeral converter
Numbers to Roman numerals and back.
Wind chill calculator
How cold the wind makes the air feel.
Heat index calculator
How hot it feels with humidity.
Dew point calculator
Dew point from temperature and humidity.
Electronics
Web & Tech
Subnet calculator
Network, mask, broadcast and hosts for IPv4.
Password generator
Strong random passwords, made in your browser.
Bandwidth calculator
Download time and data use at a given speed.
Base64 encode and decode
Convert text to and from Base64.
URL encode and decode
Percent-encode or decode a URL or text.