Length & Distance Unit Converter
Convert between metric and imperial length units — mm, cm, m, km, inches, feet, yards, miles — instantly.
All conversions route through meters using exact factors (1 inch = 2.54 cm and 1 mile = 1609.344 m are defined exactly since 1959). Common quick ones: 1 inch ≈ 2.54 cm, 1 foot ≈ 30.48 cm, 1 m ≈ 3.28 ft, 1 km ≈ 0.621 mi, 1 mile ≈ 1.609 km.
Formula
About Length & Distance Unit Converter
The length unit converter handles the metric-imperial conversions everyone needs but few remember — centimeters to inches, kilometers to miles, feet to meters, and every combination of mm, cm, m, km, inches, feet, yards and miles. Enter a value, pick the units, and get an exact result, computed through meters using the internationally defined conversion factors (1 inch = exactly 2.54 cm since 1959). It's the everyday companion for travel, DIY, shipping, screen and print sizing, recipe and craft measurements, and any time you're handed a measurement in the 'wrong' system.
How to use Length & Distance Unit Converter
- 1Enter your values into Length & Distance Unit Converter — sensible, domain-typical defaults are pre-filled so you see a real result immediately.
- 2The result recomputes live using the formula shown on the page; there is no button to press.
- 3Adjust any input to compare scenarios, then read the worked example to see the substituted numbers.
Why use Length & Distance Unit Converter?
- ✓Computes Length & Distance Unit Converter instantly in your browser — no sign-up, no upload, no server round-trip.
- ✓100% free and unlimited, with the exact formula shown: convert via meters: value × (from→m factor) ÷ (to→m factor) — e.g. 1 inch = 0.0254 m exactly, 1 mile = 1609.344 m.
- ✓Runs entirely client-side, so every value you enter stays private on your device.
- ✓Live recompute as you type, with a worked example and authoritative references for trust.
Frequently asked questions
How many centimeters are in an inch?+
Exactly 2.54 cm — this has been the defined value since the 1959 international yard and pound agreement, so it's not an approximation. From it: 1 foot = 30.48 cm, 1 yard = 91.44 cm. To go from inches to cm, multiply by 2.54; from cm to inches, divide by 2.54 (or multiply by 0.3937).
How do I convert kilometers to miles?+
Multiply km by 0.621371 (or divide by 1.609344). So 100 km ≈ 62.1 miles, and 1 mile = 1.609344 km exactly. A quick mental estimate: miles ≈ km × 0.6, or km ≈ miles × 1.6. Useful for reading speed limits, race distances and odometers when travelling between metric and imperial countries.
Why do all conversions go through meters?+
Routing every conversion through a single base unit (the meter) means you only need one factor per unit, and any unit can convert to any other without a giant lookup table of every pair. The math is value × (source-to-meter factor) ÷ (target-to-meter factor) — simple, exact, and how virtually all unit-conversion software works internally.
Are these conversions exact or rounded?+
The underlying factors are exact (defined by international standard: 1 inch = 0.0254 m, 1 mile = 1609.344 m). The displayed result is rounded for readability, but the calculation uses full precision. For engineering or legal work requiring specific significant figures, note the exact factors; for everyday use, the shown result is more than precise enough.
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