The metric (SI) system is decimal and used by most of the world. Imperial (and US customary) units dominate in the United States for everyday length, weight, and volume. Recipes, road signs, and product labels often force you to convert between the two.
Quick reference
| Metric | Imperial / US | Converter |
|---|---|---|
| 1 meter | ≈ 3.28084 feet | Open → |
| 1 kilometer | ≈ 0.621371 miles | Open → |
| 1 centimeter | ≈ 0.393701 inches | Open → |
| 1 kilogram | ≈ 2.20462 pounds | Open → |
| 1 liter | ≈ 0.264172 US gallons | Open → |
| 1 m² | ≈ 10.7639 ft² | Open → |
| 1 km/h | ≈ 0.621371 mph | Open → |
Temperature
Weather and cooking often mix Celsius and Fahrenheit. See Celsius to Fahrenheit and Fahrenheit to Celsius.
Why exact factors matter
International definitions fix many factors exactly (for example, 1 inch = 25.4 mm). UnitNest uses those exact relationships so repeated conversions stay consistent.