Conversion tools
All the unit and currency conversion calculators in one place.
Centimetres to Inches Converter
Convert centimetres to inches and inches to centimetres instantly. Accurate, fast, with rounding and handy presets.
Open tool →Grams to Ounces Converter
Convert grams to ounces and ounces to grams instantly. Choose Avoirdupois or Troy. Accurate, fast, with rounding and handy presets.
Open tool →Hours to Minutes Converter
Convert hours to minutes and minutes to hours instantly. Simple, fast, with rounding and useful presets.
Open tool →Kilojoules to Kilocalories Converter
Convert kilojoules (kJ) to kilocalories (kcal) and back instantly. Accurate, fast, with rounding options and handy presets for food labels and exercise.
Open tool →Kilometres per Hour to Miles per Hour Converter
Convert kilometres per hour (km/h) to miles per hour (mph) and back instantly. Clean, quick and accurate with handy presets.
Open tool →Litres to Gallons Converter
Convert litres to gallons and gallons to litres instantly. Choose UK (Imperial) or US gallons. Clean, quick and accurate with handy presets.
Open tool →Litres to Pints Converter
Convert litres to pints and pints to litres instantly. Choose UK (Imperial) or US pints. Accurate, fast, with rounding and presets.
Open tool →Metres per Second to Miles per Hour Converter
Convert metres per second (m/s) to miles per hour (mph) and back instantly. Accurate, fast, with rounding options and handy presets.
Open tool →Metres to Feet Converter
Convert metres to feet and feet to metres instantly. Clean, quick and accurate with handy presets for common values.
Open tool →Metres to Yards Converter
Convert metres to yards and yards to metres instantly. Clean, quick and accurate, with handy presets for common values.
Open tool →Miles to Kilometres Converter
Convert miles to kilometres and kilometres to miles instantly. Accurate, fast, with rounding options and handy presets.
Open tool →Millilitres to Fluid Ounces Converter
Convert millilitres to fluid ounces and fluid ounces to millilitres instantly. Choose UK (Imperial) or US (Customary). Accurate, fast, with rounding and presets.
Open tool →Millimetres to Inches Converter
Convert millimetres to inches and inches to millimetres instantly. Accurate, fast, with rounding and handy presets.
Open tool →Square Kilometres to Square Miles Converter
Convert square kilometres to square miles and square miles to square kilometres instantly. Accurate, fast, with rounding and handy presets.
Open tool →Square Metres to Square Feet Converter
Convert square metres to square feet and square feet to square metres instantly. Accurate, fast, with rounding and handy presets.
Open tool →Convert units and currencies without the faff
This section covers the everyday conversions people reach for most. Length, weight, area, volume, speed, temperature and time are all here, with clean inputs and results that are easy to copy. Currency and percentage style conversions sit alongside the classic unit pairs, so you can jump from miles to kilometres, kilograms to pounds, litres to pints, Celsius to Fahrenheit, or GBP to EUR in seconds.
Every page is built for speed and accuracy. If you want the method, there is a short explainer and a worked example in plain English. If you just need the answer, type your number and you are done. The layout stays consistent across devices, labels are clear and there are no distractions. More converters will be added based on demand and search behaviour, with sensible defaults and rounding where it helps.
Bookmark this hub if you price products, compare specs, plan trips or check recipes. Stable Numbers is a practical resource designed to save time, cut errors and give you confidence in the result. If there is a converter you would like to see, send a request and it will be prioritised by demand.