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Length Converter

An inch is exactly 2.54 centimeters and a mile is exactly 1,609.344 meters — both fixed by the 1959 international yard and pound agreement, which is why converting between metric and US lengths is exact, not approximate. This converter moves between meters, kilometers, centimeters, millimeters, inches, feet, yards, and miles using those precise definitions.

In Kilometers
0.001km
1 m = 0.001 km
1 m on the scale
Common references
1 ft
3.3×
1 m
1.0×
avg adult
0.55×
100 m sprint
0.01×
1 mile
6.2e-4×
Value
From
To
Exact by definition
One inch is defined as exactly 2.54 cm, so every metric-to-imperial length here is exact — not a rounded approximation.
The survey-foot trap
Old US land deeds use the survey foot, which differs from the international foot used here by 2 parts per million — trivial for a room, but it drifts by feet over survey-mile distances.
All units
Meters1
Kilometers0.001
Centimeters100
Millimeters1,000
Inches39.3701
Feet3.2808
Yards1.0936
Miles0.0006214
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Uses your inputs above
0.001 in kilometers. Want to try a variation?

The math

Reviewed 2026
Formula
Multiply or divide by the conversion factor to a base unit.

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Example: how length is calculated

Step-by-step with default inputs

Suppose you put the default values into Length Converter:

Value
1
From
Meters
To
Kilometers

Plug those into the formula Multiply or divide by the conversion factor to a base unit. and the result is:

In Kilometers
0.001km
Length units and their conversion factors
UnitSymbolIn meters
Metersm1
Kilometerskm1,000
Centimeterscm0.01
Millimetersmm0.001
Inchesin0.0254
Feetft0.3048
Yardsyd0.9144
Milesmi1,609.344

Source: NIST official conversions

How does the length converter work?

Length Converter uses the formula shown in the math card and cites NIST official conversions. Inputs are validated for sensible ranges; results are computed client-side for instant feedback and do not leave your browser.

References: NIST official conversions.

Last reviewed July 2, 2026 · Editorial policy

Frequently asked questions

How many centimeters are in an inch?

Exactly 2.54 centimeters. The inch has been defined as 2.54 cm by international agreement since 1959, so inch-to-metric conversions are exact rather than rounded.

How many feet are in a mile?

5,280 feet. A mile is defined as 1,609.344 meters and a foot as 0.3048 meters, and 1,609.344 divided by 0.3048 is exactly 5,280.

Is a meter longer than a yard?

Yes, slightly. One meter equals about 1.0936 yards, or 39.37 inches — roughly 3.4 inches longer than a yard's 36 inches.

How accurate is this length calculator?

The math is deterministic — the same inputs always produce the same output, and the formula is shown above. Accuracy of the answer for your situation depends on how well your inputs match reality and how well the formula models the question.

Why does Google show a slightly different conversion?

For most units the answer is identical to many decimal places. Differences usually come from currency rates (which fluctuate intraday — this tool shows the ECB's daily reference rates) or rounding. We display up to 4 decimals.

How do I share my result?

Hit Share at the top of the page. Every input you change is encoded in the URL, so a permalink reproduces exactly what you see. No account needed.