What's the difference between a US gallon and an imperial gallon?

A US gallon is about 3.785 L, an imperial (British) gallon about 4.546 L. This tool uses the US gallon by default, which is the most commonly seen.

How do you convert Celsius to Fahrenheit?

°F = °C × 9/5 + 32. Example: 20 °C × 1.8 + 32 = 68 °F. The tool does it live.

Why isn't 1 foot exactly 30 cm?

A foot is exactly 30.48 cm, not 30 cm. Common approximation, but imprecise.

A knot is one nautical mile per hour, roughly 1.852 km/h. Standard unit in navigation and aviation.

Conversions

Unit converter

Convert lengths, weights, volumes, temperatures, areas and speeds. All common metric and imperial units.

How to use this tool

How many meters is a mile? How much does a pound weigh in kilograms? How do you go from Fahrenheit to Celsius? This tool covers the six most common unit categories. Pick a category, source unit, target unit, enter a value — the conversion happens live, no page reload.

Concrete examples

1 mile = 1.609 km
1 pound = 0.4536 kg
1 US gallon = 3.785 L
0 °C = 32 °F = 273.15 K

Frequently asked questions

What's the difference between a US gallon and an imperial gallon?: A US gallon is about 3.785 L, an imperial (British) gallon about 4.546 L. This tool uses the US gallon by default, which is the most commonly seen.
How do you convert Celsius to Fahrenheit?: °F = °C × 9/5 + 32. Example: 20 °C × 1.8 + 32 = 68 °F. The tool does it live.
Why isn't 1 foot exactly 30 cm?: A foot is exactly 30.48 cm, not 30 cm. Common approximation, but imprecise.
What's a knot?: A knot is one nautical mile per hour, roughly 1.852 km/h. Standard unit in navigation and aviation.