Length Converter

Updated July 2026

Enter a value in any unit and convert length and distance across millimeters, centimeters, meters, kilometers, inches, feet, yards, miles and nautical miles. Type once and every unit updates instantly — the common cm ↔ inches and km ↔ miles results are highlighted. Everything runs privately in your browser.

One inch equals exactly 2.54 cm, and one mile equals about 1.609 km (1 mi = 1609.344 m). So to go from inches to cm you multiply by 2.54; to go from miles to km you multiply by 1.609.
Pick the unit you're entering. All other units update automatically.
cm ↔ inches · km ↔ miles
Centimeters (cm)
Inches (in)
Feet (ft)
Kilometers (km)
Miles (mi)
Meters (m)
Millimeters (mm)
Yards (yd)
Nautical miles (nmi)

How this length converter works

Length and distance are measured in two main systems: the metric system (millimeters, centimeters, meters and kilometers) and the imperial / US customary system (inches, feet, yards and miles). To convert accurately between them, this tool turns whatever you type into a single base unit — meters — and then expresses that base value in every other unit. Converting through a base avoids the rounding errors that creep in when you chain conversions one after another.

The exact factors used are: 1 inch = 0.0254 m, 1 foot = 0.3048 m, 1 yard = 0.9144 m, 1 mile = 1609.344 m and 1 nautical mile = 1852 m. The most-searched pairings — centimeters to inches and kilometers to miles — are highlighted at the top so you can read them at a glance.

Worked example: a distance of 5 km is 5 ÷ 1.609344 ≈ 3.107 miles, or 5,000 m, or about 16,404 ft. A height of 180 cm is 180 ÷ 2.54 ≈ 70.87 inches, which is 5 ft 10.9 in.

Common conversions

FromEquals
1 inch (in)2.54 centimeters (cm)
1 foot (ft)30.48 centimeters (cm)
1 meter (m)3.28 feet (ft)
1 mile (mi)1.609 kilometers (km)
1 kilometer (km)0.621 miles (mi)

Reference note: factors follow the international yard and pound agreement (1 yard = 0.9144 m, exact). Results are rounded for readability, so very small differences in the last decimal are normal.

Frequently asked questions

How many cm in an inch?
One inch equals exactly 2.54 centimeters. So 12 inches (one foot) is 30.48 cm, and 10 inches is 25.4 cm.
How do I convert km to miles?
Divide the number of kilometers by 1.609344, or multiply by 0.621371, to get miles. For example, 5 km ÷ 1.609344 ≈ 3.107 miles. This converter does it instantly the moment you type a value.
How many feet in a meter?
One meter equals about 3.280839895 feet, usually rounded to 3.281 ft. So a 10 m length is roughly 32.81 ft.
How many inches in a foot?
There are exactly 12 inches in one foot. One foot is 0.3048 meters, and one inch is 2.54 centimeters, so a foot is 30.48 cm.
How do I convert miles to km?
Multiply the number of miles by 1.609344 to get kilometers. For example, 10 miles × 1.609344 ≈ 16.09 km. One mile equals exactly 1609.344 meters.
What is a nautical mile?
A nautical mile equals exactly 1852 meters, which is about 1.151 statute miles or 1.852 kilometers. It is used in marine and air navigation because it corresponds to one minute of latitude.
⚡ Length Converter — by larely ↗

Related tools

Angle Converter

Convert angles between degrees, radians, gradians and turns.

Pressure Converter

Convert pressure between psi, bar, kPa, atm and mmHg.

Speed Converter

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

Time Converter

Convert time between seconds, minutes, hours, days, weeks and years.

Volume Converter

Convert volume between liters, gallons, cups, fluid ounces, mL and more.

Area Converter

Convert area between square feet, square meters, acres, hectares and more.

Energy Converter

Convert energy between joules, calories, kWh, BTU and more.

Fuel Economy Converter

Convert between MPG, L/100km and km/L fuel economy units.

Inch Fraction Converter

Convert between decimal inches, fractional inches and millimeters.

Power Converter

Convert power between watts, kilowatts, horsepower and BTU/h.

Torque Converter

Convert torque between Nm, ft-lb, in-lb and kgf-m.

Frequency Converter

Convert frequency between Hz, kHz, MHz, GHz, THz and RPM.

Browse all 251 free tools →