How to convert units
Go through one base unit: turn your number into meters (or kilograms, liters, square meters), then into the unit you want. Each step uses an exact US definition, like 1 inch = 0.0254 m. Temperatures use NIST's formulas instead, because 0 °F and 0 °C aren't the same temperature.
Here it is with your numbers:
- Turn centimeters into meters: 100 × 0.01 = 1 m.
- Turn meters into inches: 1 ÷ 0.0254 = 39.37007874… in.
- Round to 6 significant figures: 39.3701 in.
It means 100 cm and 39.3701 in are the same length.
Source NIST Handbook 44 (2026) · Appendix C, General Tables of Units of Measurement ↗NIST Guide to the SI (SP 811) · Appendix B.8, factors for units listed alphabetically ↗
Your value in every unit
| Unit | Value |
|---|---|
| Millimeters | 1,000 mm |
| Centimeters | 100 cm |
| Meters | 1 m |
| Kilometers | 0.001 km |
| Inches | 39.3701 in |
| Feet | 3.28084 ft |
| Yards | 1.09361 yd |
| Miles | 0.000621371 mi |
Answers are rounded to 6 significant figures (39.3701, 0.000621371). Very large or very small numbers are written as × 10ⁿ.
FAQs
How do you convert units?
Multiply by how big the old unit is in the new one. 1 inch is 2.54 cm, so 10 inches is 10 × 2.54 = 25.4 cm. Going the other way, divide: 25.4 cm ÷ 2.54 = 10 inches.
Source NIST Handbook 44 (2026) · Appendix C, General Tables of Units of Measurement ↗
Is 1 liter 64 oz?
No. 1 liter is 33.814 US fluid ounces. 64 fl oz is half a gallon, 1.89271 liters.
Is an acre 200 ft by 200 ft?
No, that's 40,000 square feet. An acre is 43,560 square feet, about 208.7 ft by 208.7 ft if it were a square.
Sources
- NIST Handbook 44 (2026): Appendix C, General Tables of Units of Measurement
- NIST Guide to the SI (SP 811): Appendix B.8, factors for units listed alphabetically
- NIST Guide to the SI (SP 811): Appendix B.9, conversion factors: temperature