🔄 Unit Converter
Convert between length, weight, temperature, volume, speed, area, and more — instantly.
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All Conversions
About Unit Conversion
Unit conversion is the process of expressing the same quantity using different measurement units. All unit conversions involve multiplying or dividing by a conversion factor.
The Metric System
The metric (SI) system is used by most countries and all scientific work. It's based on powers of 10, with standard prefixes: kilo (×1000), centi (×0.01), milli (×0.001), micro (×0.000001).
Common Conversions Reference
| From | To | Multiply by |
|---|---|---|
| inches | cm | 2.54 |
| miles | km | 1.60934 |
| pounds | kg | 0.453592 |
| gallons (US) | liters | 3.78541 |
| °F | °C | (F−32) × 5/9 |
Why does the US still use the imperial system? +
The US is one of three countries (along with Myanmar and Liberia) that hasn't officially adopted the metric system. Historical inertia, infrastructure costs, and cultural familiarity have kept the imperial system in everyday use, despite the US officially recognizing the metric system and using it in science, medicine, and military contexts.
What is a "metric ton" vs a "ton"? +
A metric ton (tonne) is 1,000 kg (2,204.6 lbs). A US "short ton" is 2,000 lbs (907 kg). A UK "long ton" is 2,240 lbs (1,016 kg). The metric ton is the most widely used internationally; always specify which ton you mean in international contexts.