VAT calculator
Add VAT to a net price or take it out of a total, at 10% or any rate you set.
Calculators & unit converters
Pick a calculator below. Every one runs inside your browser. What you calculate (inputs and results) is recorded to prevent illegal use. Each page shows the formula it uses and a worked example.
Money & selling
Margin calculator
Enter cost, price, shipping and fee to see the payout, profit and margin rate.
Selling price calculator
From cost, target margin, fee and discount, find the price you need to list.
Discount calculator
Find the sale price from a discount, or the discount from two prices.
Percentage calculator
Find X% of a number, what percent one number is of another, and percent change.
Dates
Date calculator
Days between two dates, countdowns, age, and adding days to a date.
Unit converters
Length converter
Convert between mm, cm, m, km, inches, feet, yards, miles and nautical miles.
Weight converter
Convert g, kg, t, oz, lb and stone. 1 lb is exactly 0.45359237 kg.
Temperature converter
Convert Celsius, Fahrenheit and Kelvin. °F = °C × 9/5 + 32, and K = °C + 273.15.
Area converter
Convert m², km², hectares, sq ft, sq yd, acres and Korean pyeong (400/121 m²).
Volume converter
Convert mL, L, m³, US and UK gallons, quarts, pints, cups, fl oz, tbsp and tsp.
Speed converter
Convert km/h, mph, m/s, knots and ft/s. 1 mph is exactly 1.609344 km/h.
Data size converter
Convert bits, bytes, KB, MB, GB, TB and KiB, MiB, GiB, TiB. 1 KB = 1000 B.
Fuel economy converter
Convert km/L, L/100 km, US mpg and UK mpg. The two mpg use different gallons.
Questions people ask
Are these calculators free?
Yes. All of them are free and need no sign-up.
Is what I type sent anywhere?
The math runs in your browser. What you calculate (inputs and results) is recorded to prevent illegal use.