Unit Converter
Length, weight, temperature and volume — metric to imperial and back, converted live in both directions.
How the converter works
Every unit in a category is defined by its ratio to a base unit (meters, grams, liters); temperature uses the exact Celsius/Fahrenheit/Kelvin formulas instead, since those scales have different zero points. You can type on either side — the other side updates instantly.
Pick a category
Length, weight, temperature or volume.
Choose the units
Source unit on the left, target on the right — e.g. inches → centimeters.
Type either side
Both fields are live: enter a value on the left or the right and the other converts immediately.
The conversions people look up most
A handful of ratios cover most everyday cases: 1 inch = 2.54 cm exactly, 1 foot = 30.48 cm, 1 mile ≈ 1.609 km, 1 kg ≈ 2.205 lbs, 1 US gallon ≈ 3.785 liters, and °F = °C × 9/5 + 32. Recipes are a classic trap: US cups measure volume (about 237 ml), so "a cup of flour" depends on the ingredient's density — for baking, converting to grams with a scale is more accurate than any cup measure.
Frequently asked questions
How do I convert inches to centimeters?
Multiply by 2.54 — one inch is exactly 2.54 cm. In the converter, choose Length, set inches on the left and centimeters on the right.
What is the formula for Celsius to Fahrenheit?
°F = °C × 9/5 + 32. So 20°C is 68°F. The converter applies this exactly, including for negative temperatures.
How many pounds is a kilogram?
One kilogram is about 2.2046 pounds. A quick mental estimate is kg × 2.2.
Are US cups and gallons used here, or UK ones?
US customary units: 1 cup = 236.588 ml and 1 gallon = 3.785 liters. UK (imperial) pints and gallons are larger — a UK gallon is about 4.546 liters.