UK units and everyday maths calculators
Convert UK imperial and metric measurements, temperatures, ratios and percentages with transparent formulas.
Choose a uk units & maths calculator
Percentage change calculator UK
Measure an increase or decrease between an original and a new value.
UK units & mathsReverse percentage calculator UK
Recover the starting value before a known percentage increase or decrease.
UK units & mathsPercentage of a total calculator UK
Find what share one amount represents of a positive total.
UK units & mathsRatio simplifier calculator UK
Reduce a two-part whole-number ratio and show each share of the total.
UK units & mathsUK length converter calculator UK
Convert metres, centimetres, millimetres, feet, inches, yards and miles.
UK units & mathsUK area converter calculator UK
Convert square feet, square metres, acres and hectares.
UK units & mathsUK imperial volume converter calculator UK
Convert litres, millilitres, cubic metres and UK imperial pints or gallons.
UK units & mathsStone, pounds and kilograms converter calculator UK
Convert between kilograms, stones, pounds, ounces and metric tonnes.
UK units & mathsCelsius and Fahrenheit converter calculator UK
Convert temperatures between Celsius, Fahrenheit and Kelvin.
UK units & mathsWhere to start
Check the unit definitions before entering a value. UK gallons and pints differ from US measures, and decimal stones are not a stones-and-pounds pair.
UK data and coverage
These tools use defined conversion factors and your figures. They do not require market data, country-specific tax rules or a location API.
Each calculator explains the formula, includes a worked example and identifies the assumptions that can affect your result. Official rule tables and dated price references are linked on the relevant pages.
Read the data sources and calculation methodology or browse all UK calculators.