Length Converter

Common Examples

Input	Result
5 ft	152.4 cm / 1.524 m / 60 in / 1.6667 yd
100 cm	1,000 mm / 1 m / 39.3701 in / 3.2808 ft
1 mi	1,609.344 m / 1.6093 km / 5,280 ft / 1,760 yd
10 km	10,000 m / 6.2137 mi / 32,808.4 ft / 10,936.1 yd
36 in	91.44 cm / 0.9144 m / 3 ft / 1 yd

How It Works

All length conversions use meters as the intermediate base unit. The process is: convert the input value to meters, then convert from meters to each target unit.

Conversion factors to meters:

1 millimeter (mm) = 0.001 m
1 centimeter (cm) = 0.01 m
1 meter (m) = 1 m
1 kilometer (km) = 1,000 m
1 inch (in) = 0.0254 m
1 foot (ft) = 0.3048 m
1 yard (yd) = 0.9144 m
1 mile (mi) = 1,609.344 m

Conversion factors from meters:

m to mm: multiply by 1,000
m to cm: multiply by 100
m to km: divide by 1,000
m to in: divide by 0.0254 (or multiply by 39.3701)
m to ft: divide by 0.3048 (or multiply by 3.28084)
m to yd: divide by 0.9144 (or multiply by 1.09361)
m to mi: divide by 1,609.344 (or multiply by 0.000621371)

These factors are based on the International System of Units (SI). One inch is defined as exactly 25.4 millimeters. One foot equals exactly 12 inches, and one yard equals exactly 3 feet. One mile equals exactly 5,280 feet.

Common Length References

Credit card length: approximately 85.6 mm / 3.37 in
Standard door height: approximately 2.032 m / 6 ft 8 in
Marathon distance: 42.195 km / 26.219 mi

Worked Example

To convert 5 feet to centimeters: First convert to meters: 5 x 0.3048 = 1.524 m. Then convert from meters to centimeters: 1.524 / 0.01 = 152.4 cm. To inches: 1.524 / 0.0254 = 60 in. To yards: 1.524 / 0.9144 = 1.6667 yd. This confirms the well-known relationship that 1 foot = 12 inches, since 5 feet = 60 inches.

Related Calculators

Weight Converter

Convert between pounds, kilograms, ounces, grams, and stone instantly.

Temperature Converter

Convert between Fahrenheit, Celsius, and Kelvin instantly.

Speed Converter

Convert between mph, km/h, m/s, ft/s, and knots instantly.

Frequently Asked Questions

How many centimeters are in an inch?

There are exactly 2.54 centimeters in one inch. This is an exact definition established by international agreement in 1959. To convert inches to centimeters, multiply by 2.54. To convert centimeters to inches, divide by 2.54.

How many feet are in a mile?

There are exactly 5,280 feet in one mile. This equals 1,760 yards or 1,609.344 meters. The mile was historically defined as 1,000 Roman paces (mille passus), but the modern statute mile is based on the foot.

What is the difference between metric and imperial length units?

Metric units (mm, cm, m, km) are based on the meter and scale by powers of 10, making conversions straightforward. Imperial units (in, ft, yd, mi) have less uniform relationships: 12 inches per foot, 3 feet per yard, 1,760 yards per mile. Most countries use metric; the United States primarily uses imperial.

How do I convert between kilometers and miles?

Multiply kilometers by 0.621371 to get miles, or multiply miles by 1.60934 to get kilometers. A quick approximation: 1 km is roughly 0.62 miles, and 1 mile is roughly 1.61 km. For a 5K race, that is approximately 3.1 miles.

How accurate are these conversions?

The conversion factors used here are precise to at least 6 significant digits and are based on the internationally agreed-upon definitions. One inch is defined as exactly 25.4 mm, so all imperial-to-metric conversions derived from this are exact. For everyday measurements, this level of precision is more than sufficient.