Unit Converter

How to use

1. Pick Length, Weight or Temperature.
2. Enter a value and choose the from/to units.
3. The result updates as you type.

About this tool

This converter covers the everyday units for length, weight and temperature with precise factors.

All math runs in your browser.

How it works

Length and weight conversions are simple scaling: every unit is defined as a fixed multiple of a base unit (meters for length, kilograms for weight). Converting is multiply-by-the-ratio — for example, inches to centimeters is always x 2.54, exactly.

Temperature is the odd one out because the scales start at different zeros. Celsius to Fahrenheit is F = C x 9/5 + 32, and back is C = (F - 32) x 5/9. Kelvin is Celsius shifted by 273.15, with no scaling involved.

A quick sanity check catches most conversion mistakes: metric lengths are bigger numbers than imperial for the same distance (170 cm vs 5 ft 7 in), while metric weights are smaller numbers (65 kg vs 143 lb). If your answer breaks that pattern, you probably multiplied when you should have divided.

Worked examples

5 ft 7 in to centimeters: 67 inches x 2.54 = 170.18 cm, about 170 cm.

100 F to Celsius: (100 - 32) x 5/9 = 68 x 5/9 = 37.8 C — just above normal body temperature.

Quick reference

Frequently asked questions

More free tools