Quick guide to unit conversion
Different countries use different measurement systems. Most of the world uses the metric system (meters, kilograms, liters), while the United States commonly uses imperial or US customary units (feet, pounds, gallons). This converter helps you move between them instantly.
Common conversions
- 1 inch = 2.54 centimeters
- 1 foot = 0.3048 meters
- 1 mile = 1.609 kilometers
- 1 pound = 0.4536 kilograms
- 1 US gallon = 3.785 liters
Converting temperature
Temperature scales do not share a common zero, so conversion uses formulas rather than a simple multiplier. To convert Celsius to Fahrenheit, multiply by 9/5 and add 32. To convert Fahrenheit to Celsius, subtract 32 and multiply by 5/9. Kelvin equals Celsius plus 273.15.
Why accurate conversion matters
From cooking and travel to engineering and science, small conversion mistakes can cause big problems. This tool uses exact international conversion factors and rounds results to eight significant digits.
Frequently asked questions
Which units are supported?
Length, weight, volume, speed and temperature, with the most common units in each category.
Are US and UK gallons the same?
No. This tool uses US gallons. A UK (imperial) gallon is about 4.546 liters.
How precise are the results?
Results use exact conversion factors and are shown with up to eight significant digits.