Learn the conversion factors for inches, centimeters, feet, meters, miles, and kilometers, with worked examples for converting in either direction.
Converting length units comes up constantly: reading a recipe in centimeters when you know inches, following a fitness app that logs miles instead of kilometers, or checking whether furniture will fit through a doorway measured in a different unit than you’re used to. Every conversion comes down to one multiplication using the right conversion factor.
To convert any length from one unit to another, multiply by the conversion factor between them:
The trick is making sure the conversion factor points the right way — multiplying when going from a larger unit to a smaller one, and either multiplying by a fraction or dividing when going the other way.
| From | To | Multiply By |
|---|---|---|
| Inches | Centimeters | 2.54 |
| Feet | Meters | 0.3048 |
| Miles | Kilometers | 1.60934 |
| Yards | Meters | 0.9144 |
| Meters | Feet | 3.28084 |
| Kilometers | Miles | 0.62137 |
Inches to centimeters: 12 inches × 2.54 = 30.48 cm.
Miles to kilometers: 5 miles × 1.60934 = 8.05 km (rounded to 2 decimal places).
Meters to feet: 2 meters × 3.28084 = 6.56 feet.
To reverse a conversion, either use the reciprocal factor from the table above, or divide by the original factor instead of multiplying. For example, to convert 30.48 cm back to inches: 30.48 ÷ 2.54 = 12 inches — the same result as multiplying by the reciprocal factor, 0.3937.
Most everyday conversions are fine rounded to 2 decimal places, but for anything precise — construction, engineering, recipes that need to scale exactly — use the full conversion factor rather than a rounded shortcut, since small rounding errors compound when a value is converted more than once.
Length Converter
Multiply the number of inches by 2.54. For example, 10 inches times 2.54 equals 25.4 centimeters.
Multiply the number of miles by 1.60934. For example, 3 miles times 1.60934 equals about 4.83 kilometers.
Using a conversion tool avoids memorizing every conversion factor and rounding by hand — you enter a value once and get an accurate result in whichever unit you need.
This is almost always rounding. Conversion factors like 1.60934 (miles to kilometers) are often shortened to fewer decimal places by hand, which introduces small differences that grow with larger numbers or multiple conversions.
Find the right tool, or keep reading Brekzy's other guides.