Unit Converter
Convert between common units of length, weight, volume, area, speed, time, and temperature. Imperial ↔ Metric.
length: mm cm m km in ft yd mi · weight: mg g kg oz lb ton · volume: ml l fl-oz cup pint quart gallon · area: cm2 m2 km2 in2 ft2 acre hectare · speed: m/s km/h mph knots · time: sec min hr day week year · temperature: C F K
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Frequently asked questions
Why is the unit field free-text instead of a dropdown?
A free-text field lets you type unit abbreviations directly (ft, kg, mph) and supports the full set across all categories with one keyboard. The help text under each field lists the valid units for the selected category.
Which gallon — US or Imperial?
This calculator uses US gallons (3.78541 liters). The Imperial gallon (used in the UK) is 4.54609 liters, about 20% larger. If you need Imperial conversion, multiply the US result by 0.832674.
What is the difference between weight and mass?
Mass is the amount of matter (kilograms); weight is the force gravity exerts on that mass (newtons). On Earth at sea level the two are commonly conflated, and this tool follows the everyday convention.