Length Converter
Convert any length or distance between metric and imperial units.
From
To
- 1
Convert to the target unit
1 m ÷ 0.3048 = 3.280840 ft
1 m =
| Millimeter | 1,000 mm |
| Centimeter | 100 cm |
| Kilometer | 0.001 km |
| Inch | 39.370079 in |
| Foot | 3.28084 ft |
| Yard | 1.093613 yd |
| Mile | 0.000621 mi |
| Nautical mile | 0.00054 nmi |
How this is calculated
This converter works by routing every value through a single base unit: the meter, the SI standard for length. Each supported unit carries a fixed "to-base" factor that says how many meters one of that unit equals — for example 1 inch = 0.0254 m, 1 foot = 0.3048 m, 1 mile = 1609.344 m, and 1 nautical mile = exactly 1852 m. These are exact international definitions, not approximations, so conversions are reversible without drift.
The math is two steps. First your input is multiplied by the source unit's factor to get a value in meters (base = value x fromFactor). Then that base value is divided by the target unit's factor to express it in the destination unit (result = base / toFactor). Combining the two steps means the conversion is just value x (fromFactor / toFactor), which is why it scales linearly and 0 always maps to 0.
Length has no offset (unlike temperature), so no addition or subtraction is involved — only scaling. The only practical limitation is display rounding: results are shown to a fixed number of decimal places, so very large or very small magnitudes may appear truncated even though the underlying ratio is exact.
Examples
| Input | Result |
|---|---|
| Convert 5 miles to kilometres | 8.04672 km (5 x 1.609344) |
| Convert 100 metres to feet | 328.084 ft (100 x 3.28084) |
| Convert 10 kilometres to miles | 6.21371 mi (10 / 1.609344) |
| Convert 12 inches to centimetres | 30.48 cm (12 x 2.54) |
About this calculator
A length converter changes a distance from one unit of measurement into another, bridging the metric system (millimetres, centimetres, metres, kilometres) and the imperial or US customary system (inches, feet, yards, miles). It is the tool you reach for when a recipe, manual, map, or product spec uses units you do not normally think in.
Conversion works by multiplying or dividing by a fixed factor that is defined by international agreement. Since 1959 the inch has been exactly 25.4 millimetres, which makes every other relationship exact: one foot is 0.3048 metres, one yard is 0.9144 metres, and one mile is 1.609344 kilometres. The converter chains these factors so that, internally, every value is reduced to a common base unit (metres) and then expanded into whatever unit you ask for.
Using it takes three steps. Enter the number you want to convert, choose the unit you are starting from, and choose the unit you want the answer in. The result appears immediately, and you can reverse the direction or change either unit without retyping the number.
Interpreting the output is usually straightforward, but keep an eye on scale. Metric units step by powers of ten (1 km = 1000 m = 100000 cm), so moving the decimal point is often a quick mental check. Imperial steps are irregular: 12 inches to a foot, 3 feet to a yard, 1760 yards to a mile. When a converted figure looks surprising, comparing it against one of these known anchors will tell you whether it is right.
The classic mistakes are confusing centimetres with millimetres (a factor of ten) and mixing US and UK definitions of miles for niche cases. For everyday distances the international definitions used here are universal, so the only real risk is choosing the wrong unit in the dropdown. Double-check the from and to labels before trusting a result that drives a purchase or a cut.
Frequently asked questions
Exactly 1.609344 kilometres. The mile is defined as 1760 yards, and since the yard is exactly 0.9144 metres, the conversion factor is fixed and precise rather than approximate.
One inch equals exactly 2.54 centimetres, because the inch has been internationally defined as 25.4 millimetres since 1959. To go from inches to centimetres multiply by 2.54; to reverse it, divide by 2.54.
Multiply metres by about 3.28 to estimate feet. For a rough mental version, multiply by 3 and add a bit; for example 10 metres is roughly 33 feet (32.8 feet to be exact).
No. A nautical mile is 1852 metres, used in aviation and shipping, while a statute (land) mile is 1609.344 metres. They are different units, so do not mix them when converting marine or flight distances.
Metric units scale by powers of ten, so converting between millimetres, centimetres, metres, and kilometres just moves the decimal point. Imperial units use irregular steps such as 12, 3, and 1760, which is why a converter is handy.
Also known as
TG we-Calculate Editorial Team. (2026). Length Converter [Online calculator]. TG we-Calculate. https://we-calculate.com/calculator/length-converter
TG we-Calculate Editorial Team. "Length Converter." TG we-Calculate. 2026. https://we-calculate.com/calculator/length-converter.
TG we-Calculate Editorial Team, "Length Converter," TG we-Calculate, 2026. [Online]. Available: https://we-calculate.com/calculator/length-converter
@misc{wecalculate_length_converter, title = {Length Converter}, author = {{TG we-Calculate Editorial Team}}, howpublished = {\url{https://we-calculate.com/calculator/length-converter}}, year = {2026}, note = {TG we-Calculate} }
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