Length Converter
Convert between metric and imperial length units instantly.
Short answer: Convert between meters, kilometers, miles, feet, inches, and centimeters instantly — type a value, pick your units, and the result updates live. Handy for DIY projects, travel planning, recipes, homework, and any moment the world hands you the wrong unit system.
Last updated: October 13, 2026
How it works
Pick a unit on the left, a unit on the right, and type a value — the conversion happens instantly as you type, and the sentence under the result spells it out (“1 mile equals 1.609344 kilometers”). The ↔ button swaps the direction without retyping anything.
Every conversion routes through meters using exact definition factors: an inch is exactly 2.54 centimeters, a foot exactly 30.48 centimeters, and a mile exactly 1.609344 kilometers, so round trips come back clean.
A worked example
The tool loads with the conversion most people need on a trip:
Change the value to 26.2 and you have a marathon in kilometers (about 42.16). Swap the units and 100 kilometers becomes about 62.14 miles — handy for European road signs and race distances.
Frequently asked questions
Which units can I convert?
Meters, kilometers, miles, feet, inches, and centimeters — the metric and imperial lengths that cover driving distances, heights, and everyday measurements.
How accurate are the conversions?
They use the exact international definitions (1 inch = 2.54 cm exactly), and results are shown to 12 significant digits, so conversions are precise well beyond everyday needs.
How do I convert in the opposite direction?
Press the ↔ swap button between the unit pickers. The value stays put and the result recalculates the other way around.
Can I convert weight, temperature, or volume?
This converter focuses on length only, which keeps it fast and exact. Weight and temperature use different scales and are not covered here.
Why does 1 foot show as 0.999999 sometimes?
It should not here: factors are exact decimals and results are rounded to 12 significant digits, so a foot converts to exactly 30.48 centimeters and back again.
Is 1 inch exactly 2.54 centimeters?
Yes — exactly, by international agreement since 1959. It is a definition, not a measurement, which is why conversions built on it do not drift.
How many feet are in a meter?
3.28084 feet. Conversely, one foot is exactly 0.3048 meters — the two factors are reciprocals of each other.
Why do converted values show so many decimal places?
The converter uses full-precision factors and rounds nothing until the end. For everyday use, round the final answer yourself — one decimal is plenty for a person's height, while machining work may need three or four.
Metric and imperial, precisely
The metric system is built on tens: 10 millimeters to a centimeter, 100 centimeters to a meter, 1,000 meters to a kilometer. The imperial system is historical: 12 inches to a foot, 3 feet to a yard, 1,760 yards to a mile. Converting between them is where the mistakes happen, because the factors are not round numbers — they are exact definitions agreed internationally in 1959.
The anchor facts: 1 inch is exactly 2.54 centimeters. From that single definition everything else follows — 1 foot is exactly 30.48 cm (12 × 2.54), 1 yard is 0.9144 m, and 1 mile is exactly 1,609.344 m. Going the other way, 1 meter is 3.28084 feet and 1 kilometer is 0.621371 miles. This converter uses the full-precision factors, not rounded ones, so repeated conversions do not drift.
When precision matters
For everyday use — a person's height, a room's dimensions — rounding to one decimal is fine. For construction, machining, or engineering, it is not: the difference between 2.54 and a rounded 2.5 accumulates fast. Ten inches at the rounded factor gives 25 cm; at the exact factor, 25.4 cm — nearly half a centimeter of error from one rounding decision. As a rule, convert with full precision and round only the final answer, never the factor.
A 6-foot fence → meters: 6 × 0.3048 = 1.8288 m.
Converting heights written as feet-and-inches is the most common real-world case, and the reliable method is the one above: collapse everything to the smaller unit first (inches), then convert once. Converting feet and inches separately and adding invites rounding error.
How many inches are in a centimeter?
One centimeter equals 0.3937 inches, and one inch is exactly 2.54 centimeters by international definition. For quick mental math, remember 1 inch ≈ 2.5 cm: a 30 cm ruler is just under 12 inches.
The converter uses the exact 2.54 factor, so results match engineering and manufacturing standards precisely — important when measurements feed into cutting, printing, or ordering materials.
How do I convert miles to kilometers?
Multiply miles by 1.60934. A 26.2-mile marathon is 42.16 km, and a 60 mph speed limit is about 96.5 km/h. To go the other way, divide kilometers by the same number — or multiply by 0.6214 for a close approximation.
This is the conversion travelers hit most: US road signs read in miles while rental-car dashboards abroad read in kilometers. Converting your usual cruising speed before you drive saves an uncomfortable guess at 130 km/h.
How many feet are in a meter?
One meter equals 3.28084 feet, and one foot is exactly 0.3048 meters. So a 2-meter ceiling clearance is about 6 feet 7 inches — worth knowing before renting a tall vehicle abroad.
For rough estimates, 1 meter ≈ 3 feet 3 inches gets you close enough for furniture shopping and room layouts.