Instantly convert any length or distance between metric, imperial, nautical, and astronomical units.
A length converter lets you switch instantly from one unit of measurement to another. Whether you're reading blueprints in centimeters, planning road trips in miles, or working with tech specs in inches — this tool eliminates manual calculation errors.
In the United States, both the US customary system (feet, inches, miles) and the metric system are in everyday use. Science, medicine, and international trade rely on metric units, while construction, everyday measurement, and highway distances favor US customary units. A quick converter bridges both worlds.
All conversions use a two-step method: the source value is first converted to meters (the SI base unit), then from meters to the target unit.
where f is the number of meters per unit (conversion factor). Example: 1 foot = 0.3048 m and 1 kilometer = 1,000 m.
The Empire State Building stands 443 m (1,454 ft) to the roof, or 443 m (1,454 ft) to the tip of the antenna at 443 m. In standard figures: roof height 1,454 ft (443 m), total height with antenna 1,860 ft (443 m). American architecture uses feet; international publications add meters.
The cross-country drive from New York City to Los Angeles via I-40 is approximately 2,790 miles (4,490 km). US highway signs show miles; metric equivalents appear in international travel guides and navigation apps set to metric.
The average American man is about 5 ft 9 in tall (175 cm). Medical records and driver's licenses in the US use feet and inches; international health databases and most scientific literature report height in centimeters.
A standard NFL football field is 100 yards (300 ft / 91.44 m) long and 53⅓ yards (160 ft / 48.76 m) wide, for a total playing area of 5,333 yd² (49.92 m²). Americans use yards and feet; FIFA and international sports bodies use meters.
Enter a numeric value in the input field.
Select the source unit from the dropdown menu. Units are grouped into Metric, Imperial/US, and Others.
Results appear instantly in three grouped sections.
Expand the 'Other Units' grids to see additional units, including mixed formats (meters + centimeters, feet + inches).
Change the source unit to convert in the opposite direction; the entered value stays the same.
1 inch = exactly 25.4 mm — internationally defined since 1959.
1 nautical mile = 1,852 m — equals one arcminute of latitude along any meridian.
1 light-year ≈ 9.46 × 10¹⁵ m — distance light travels in a vacuum in one Julian year.
Ångström (Å = 10⁻¹⁰ m) — used in atomic physics for wavelengths of visible light.
Thou (mil) = 1/1,000 inch = 25.4 μm; used in precision machining and PCB design.
One inch is exactly 2.54 centimeters. This ratio was established by international agreement in 1959. So 1 foot = 30.48 cm and 1 yard = 91.44 cm.
Multiply the number of feet by 0.3048. For example: 6 feet = 1.8288 m. To go back, multiply meters by 3.28084 to get feet.
A statute mile = 1,609.344 m; a nautical mile = 1,852 m (about 15% longer). The nautical mile is used in maritime and aviation navigation because it equals one arcminute of geographic latitude.
One light-year ≈ 9,460,730,472,580.8 km — nearly 9.46 trillion kilometers. That's the distance light travels in a vacuum in 365.25 days.
An ångström (Å) = 10⁻¹⁰ m = 0.1 nm. It's used in atomic physics, chemistry, and crystallography to express wavelengths of visible and X-ray light and the sizes of atoms and chemical bonds.
This converter uses exact or high-precision conversion factors from international standards (SI, NIST, IEEE). Results are accurate to at least 10 significant figures.
This converter is provided for informational and educational purposes only. For critical engineering, legal, or scientific measurements, always verify values with calibrated instruments or certified measurement standards.