A length converter is a free online tool that instantly converts any measurement of length or distance between all major metric and imperial units — meters, kilometers, miles, feet, inches, centimeters, millimeters, yards, nautical miles, and more — with complete accuracy and no manual calculation required. Enter a value in any unit and see the equivalent in every other unit simultaneously, updated in real time as you type.
The International System of Units (SI) defines the meter as the base unit of length. All other metric units are decimal multiples or fractions of the meter. The metric system's defining characteristic is its decimal base — every unit is related to adjacent units by a factor of exactly 10. There are 10 millimeters in a centimeter, 100 centimeters in a meter, 1,000 meters in a kilometer. Converting between metric units requires only moving a decimal point.
The imperial system evolved organically over centuries from historical standards — the foot (from a human foot), the inch (from the width of a thumb), the yard (3 feet). The irregular relationships — 12 inches to a foot, 3 feet to a yard, 1,760 yards to a mile, 5,280 feet to a mile — must be memorised individually because they follow no consistent mathematical pattern.
| Unit | Symbol | Meters Equivalent |
|---|---|---|
| Millimeter | mm | 0.001 m |
| Centimeter | cm | 0.01 m |
| Meter (base unit) | m | 1 m |
| Kilometer | km | 1,000 m |
| Inch | in | 0.0254 m |
| Foot | ft | 0.3048 m |
| Yard | yd | 0.9144 m |
| Mile | mi | 1,609.344 m |
| Nautical Mile | nmi | 1,852 m |
| Convert | To | Multiply By |
|---|---|---|
| Kilometers (km) | Miles (mi) | × 0.62137 |
| Miles (mi) | Kilometers (km) | × 1.60934 |
| Meters (m) | Feet (ft) | × 3.28084 |
| Feet (ft) | Meters (m) | × 0.3048 |
| Inches (in) | Centimeters (cm) | × 2.54 |
| Centimeters (cm) | Inches (in) | × 0.3937 |
| Yards (yd) | Meters (m) | × 0.9144 |
| Miles (mi) | Feet (ft) | × 5,280 |
| Feet & Inches | Centimeters | Meters |
|---|---|---|
| 5 ft 0 in | 152.4 cm | 1.524 m |
| 5 ft 4 in | 162.6 cm | 1.626 m |
| 5 ft 6 in | 167.6 cm | 1.676 m |
| 5 ft 7 in | 170.2 cm | 1.702 m |
| 5 ft 10 in | 177.8 cm | 1.778 m |
| 6 ft 0 in | 182.9 cm | 1.829 m |
| 6 ft 2 in | 188.0 cm | 1.880 m |
| 6 ft 4 in | 193.0 cm | 1.930 m |
| Race | Kilometers | Miles |
|---|---|---|
| 5K | 5.000 km | 3.107 mi |
| 10K | 10.000 km | 6.214 mi |
| Half Marathon | 21.098 km | 13.109 mi |
| Marathon | 42.195 km | 26.219 mi |
| 50K Ultra | 50.000 km | 31.069 mi |
| 100 Miles Ultra | 160.934 km | 100.000 mi |
| Landmark | Meters | Feet |
|---|---|---|
| Eiffel Tower | 330 m | 1,083 ft |
| Burj Khalifa | 828 m | 2,717 ft |
| Empire State Building | 443 m | 1,454 ft |
| Statue of Liberty | 93 m | 305 ft |
| Big Ben (Elizabeth Tower) | 96 m | 315 ft |
| Mount Everest | 8,849 m | 29,032 ft |
Since 1983, the meter has been defined as the distance light travels in vacuum in exactly 1/299,792,458 of a second. This definition is based on fixing the numerical value of the speed of light at exactly 299,792,458 meters per second — making the meter reproducible to arbitrary precision anywhere in the universe using only fundamental physical constants. The international anchor conversion (1 inch = 25.4 mm) was fixed in 1959, making all imperial-metric conversions mathematically exact.
Yes. This online length converter is 100% free with no registration, no subscription, and no payment required. Convert as many measurements as you need.
There are exactly 3.28084 feet in one meter. Equivalently, one foot equals exactly 0.3048 meters — this exact conversion is internationally standardised. One inch = 25.4 mm exactly, making 1 foot = 0.3048 m exactly.
One statute mile equals exactly 1.60934 kilometers. Equivalently, one kilometer equals 0.62137 miles. The common mental math approximation is 1 mile ≈ 1.6 km and 5 miles ≈ 8 km — useful for quick estimation but not for precise calculation.
A nautical mile is 1,852 meters — defined as one minute of arc of latitude along any meridian of the Earth. A statute mile (the regular mile used in everyday measurement) is 1,609.344 meters. A nautical mile is approximately 15% longer than a statute mile. Nautical miles are used in maritime navigation and aviation internationally.
Convert feet to inches first (multiply feet by 12), add the remaining inches, then multiply the total inches by 2.54. For example, 5 feet 9 inches: (5 × 12) + 9 = 69 inches. 69 × 2.54 = 175.26 centimeters.
A meter (1.0 m) is longer than a yard (0.9144 m) by approximately 9.36%. One meter = 1.09361 yards. One yard = 0.9144 meters. Despite being similar in everyday contexts, treating meters and yards as equivalent in any precise application introduces a consistent ~9% error.
The United States uses miles for road distances and everyday measurement. The United Kingdom uses miles for road distances (road signs show miles and mph) but uses kilometers in many other contexts. Essentially all other countries use kilometers for road distances and everyday measurement.
Use our free Free Online Length Converter — no signup, no download, works instantly on any device.
Open Free Online Length Converter — Free →