Length Converter
This length converter changes between millimeters, centimeters, meters, kilometers, inches, feet, yards, and miles, all at once. Type a value in any unit and every other unit updates live, so cm to inches, feet to cm, or km to miles takes a single entry. Below you'll find a quick conversion chart and the exact factors, in case you'd rather work it out yourself.
- cm, in, ft, m
- km & miles
- All units at once
- Conversion chart
- Live as you type
Last updated June 17, 2026 1 inch = 2.54 cm Reviewed by the Calcowa team
Type any value and every unit updates live. Decimals are fine.
100 cm ÷ 2.54 = 39.37 in
How do you convert cm to inches?
To convert centimeters to inches, divide by 2.54, since one inch is exactly 2.54 cm. So 10 cm is 3.94 inches, 30 cm is 11.81 inches, and 100 cm is 39.37 inches. To go from inches to centimeters, you'll multiply by 2.54 instead. It's a single step either way, and the converter above runs both as you type, so you won't need to remember which direction multiplies.
How do you convert feet to cm?
Multiply the feet by 30.48, because one foot is 30.48 cm. So 5 feet is 152.4 cm and 6 feet is 182.9 cm. This pair comes up a lot for height, since many forms outside the US want centimeters. If you've got feet and inches, like 5 ft 9 in, the simplest route is to turn it into total inches (69) and multiply by 2.54, which gives about 175 cm. The converter does whole feet straight away, and you'll see meters too.
How do you convert km to miles?
To convert kilometers to miles, multiply by 0.6214, or divide by 1.609. So 5 km is 3.1 miles, 10 km is 6.2 miles, and a marathon's 42.2 km is 26.2 miles. One mile is 1.609344 km exactly. Going the other way, miles to km, you multiply by 1.609. Runners use this one constantly, and the converter keeps the decimals straight so you'll keep your splits honest. Meters to feet is just as easy: 1 meter is 3.2808 feet.
Metric and imperial length units
The metric units scale by tens: 10 mm make a cm, 100 cm make a meter, and 1,000 meters make a kilometer, so converting between them just shifts the decimal. The imperial units use mixed steps instead: 12 inches make a foot, 3 feet make a yard, and 1,760 yards make a mile. That mix is what makes imperial conversions feel awkward, and that's why a tool helps. This converter bridges both systems, so you don't have to juggle the factors in your head.
Length conversion chart
Common length conversions, rounded for everyday use, so you'll grab them at a glance.
| From | Equals | From | Equals |
|---|---|---|---|
| 1 cm | 0.39 in | 5 cm | 1.97 in |
| 10 cm | 3.94 in | 1 in | 2.54 cm |
| 12 in | 30.48 cm | 1 ft | 30.48 cm |
| 5 ft | 152.4 cm | 6 ft | 182.9 cm |
| 1 m | 3.28 ft | 1 km | 0.621 mi |
| 1 mi | 1.609 km | 5 km | 3.107 mi |
Converting a weight instead? You'll want the weight converter for kg, pounds, and more, and there's a full set on the converters hub.
Frequently asked questions
What is 5 feet 9 inches in cm?
5 ft 9 in is about 175 cm. Turn it into 69 total inches, then multiply by 2.54. That's why it lands close to 175, a common height on metric forms.
Divide the centimeters by 2.54, since one inch is exactly 2.54 cm. So 10 cm is about 3.94 inches, and 30 cm is 11.81 inches. To go the other way, from inches to cm, multiply by 2.54 instead. This length converter does both directions the moment you type, so you don't have to reach for the factor each time.
Multiply the feet by 30.48, because one foot is 30.48 cm. So 5 feet is 152.4 cm and 6 feet is 182.9 cm. If you've got feet and inches together, like 5 ft 9 in, convert each part or just enter the total inches. The converter handles whole feet directly, and you'll see centimeters and meters at once.
Multiply the kilometers by 0.6214, or divide by 1.609. So 5 km is about 3.1 miles, 10 km is 6.2 miles, and a 21.1 km half marathon is 13.1 miles. One mile is 1.609344 km exactly. Switch the From unit to kilometers and the To unit to miles above, and you'll see the answer instantly.
There are 100 cm in a meter, 1,000 mm in a meter, and 1,000 m in a kilometer. The metric units scale by tens, so converting between them just moves the decimal point. That's why metric math is quick: 2.5 m is 250 cm, and 250 cm is 2,500 mm, no awkward factors involved.
Metric units (mm, cm, m, km) scale by powers of ten, while imperial units (inch, foot, yard, mile) use mixed steps: 12 inches to a foot, 3 feet to a yard, 1,760 yards to a mile. That mix is why imperial conversions feel fiddly. The converter bridges the two, so you can move from feet to meters or miles to km without the mental math.
Turn your height into total inches, then multiply by 2.54. So 5 ft 9 in is 69 inches, which is about 175 cm. A quick path is to enter the feet in the converter for the centimeters, then add the extra inches times 2.54. Many forms abroad want height in cm, so it's a common one.
Related calculators
More converters and everyday tools.
kg, pounds, ounces, and more.
Temperature converterCelsius, Fahrenheit, Kelvin.
Area calculatorSquare footage and land area.
Converting lengths?
Switch any unit above, or browse the full converters hub.