Unit Converter (length, weight, area, volume, speed)
Convert meters, inches, pounds, gallons, km/h and more between length, weight, area, volume and speed units using exact definitions. Type in either box to convert both ways.
- Runs in your browser (no upload)
Type in either box and the other one is calculated automatically.
Result
The same value in other units
| Unit | Value |
|---|---|
| Millimeter (mm) | 1,000,000 |
| Centimeter (cm) | 100,000 |
| Meter (m) | 1,000 |
| Kilometer (km) | 1 |
| Inch (in) | ≈ 39,370.0787402 |
| Foot (ft) | ≈ 3,280.83989501 |
| Yard (yd) | ≈ 1,093.61329834 |
| Mile (mi) | ≈ 0.621371192237 |
| Nautical mile (nmi) | ≈ 0.539956803456 |
"=" marks an exact result; "≈" marks a value rounded to the digits shown.
How to use
- Choose what to convert: length, weight, area, volume or speed.
- Pick the two units and type a number in either box. The other box is calculated automatically.
- The conversion factor and the value in every other unit are shown too. Use "Swap units" to convert the other way round.
FAQ
Are the conversion factors exact?
Yes. The tool uses the internationally agreed definitions, such as 1 inch = 2.54 cm, 1 pound = 0.45359237 kg, 1 US gallon = 231 cubic inches (3.785411784 L) and 1 imperial gallon = 4.54609 L, and calculates in decimal. Only results that do not divide evenly are rounded to the digits shown and marked with "≈".
Is a US gallon the same as an imperial gallon?
No. A US gallon is about 3.785 L and an imperial (UK) gallon is about 4.546 L. Fluid ounces also differ (US about 29.57 mL, UK about 28.41 mL), so they are separate units.
Is 1 mL the same as 1 cm³?
Yes. A liter is defined as one cubic decimeter, so 1 mL = 1 cm³.
How many m/s is 36 km/h?
1 km/h is 1000 m per 3600 seconds, so 36 km/h = 10 m/s. A knot is one nautical mile (1852 m) per hour.
Notes & limitations
- What you enter is processed only on this page and is not sent to YUCTS servers.
- Feet, miles and acres use the international foot (0.3048 m). The US survey foot, traditional regional units and cooking cups or spoons (which differ by country) are not included.
- Ounces and pounds are avoirdupois units for everyday weights, not the troy ounce used for precious metals.
- Results that do not divide evenly are rounded to the chosen number of significant digits. Increase the digits if you need more precision.
- Negative values and values above 10¹⁵ cannot be entered.
Data sources
- NIST Handbook 44, Appendix C: General Tables of Units of Measurement(opens in a new tab) (2026) — Checked on: 2026-11-06
- NIST SP 811, Appendix B.8: Factors for Units Listed Alphabetically(opens in a new tab) — Checked on: 2026-11-06
- UK Weights and Measures Act 1985, Schedule 1(opens in a new tab) — Checked on: 2026-11-06
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