Convert between length, weight, temperature, area, speed, and more.
Unit conversion is translating a measurement from one unit system to another. The world uses two main systems: metric (meters, kilograms, Celsius) used by most countries, and imperial (feet, pounds, Fahrenheit) used primarily in the United States. International work constantly requires converting between them.
Common conversions include length (inches to centimeters), weight (pounds to kilograms), temperature (Fahrenheit to Celsius), volume (gallons to liters), and speed (mph to km/h). Temperature is the trickiest because it uses different formulas rather than simple multiplication — °C = (°F - 32) × 5/9.
This tool covers the most-used categories: length, weight, temperature, area, volume, and speed. Each conversion uses precise conversion factors and handles decimal precision automatically. Useful for cooking, travel, engineering, fitness tracking, and any cross-border collaboration.
This tool in other languages:
Français:
Convertisseur d'unités
Español:
Convertidor de unidades
Deutsch:
Einheitenrechner
Português:
Conversor de unidades
日本語:
単位変換ツール
中文:
单位换算工具
한국어:
단위 변환기
العربية:
محول الوحدات
Pick the category (length, weight, temperature, area, speed, volume, etc.), select the "from" and "to" units, and enter a value. The converted result appears instantly. Click the swap icon to reverse direction. No signup, runs in your browser.
Length (meters, feet, inches, miles, km), weight/mass (grams, kg, pounds, ounces), temperature (Celsius, Fahrenheit, Kelvin), area (square meters, acres, hectares), speed (km/h, mph, knots, m/s), volume (liters, gallons, cups, ml), and more. Each category includes the most common international and US units.
The formula is F = C × 9/5 + 32. So 20°C is 68°F, 100°C is 212°F, and -40°C equals -40°F (the only point where they match). This tool handles the conversion automatically — just pick temperature category and the two units.
A UK imperial gallon is about 20% larger: 4.546 liters vs 3.785 liters for US gallons. This affects everything from gas mileage (MPG is not comparable across US/UK) to recipe measurements. The converter has both available — pick the right one for your context.
Most unit conversions involve irrational or long-decimal ratios (1 inch = 25.4 mm exactly, but 1 mile = 1.609344 km). The tool rounds to a reasonable number of decimal places for display. For engineering work requiring high precision, use specialized software with explicit precision control.