Length Converter
Centimetres, inches, feet, miles, and more — all at once.
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Decimals and fractions both work — 1.5 or 1 1/2.
1 cm = 0.3937008 in
1 cm in every other unit
- Nanometre (nm)10,000,000
- Micrometre (µm)10,000
- Millimetre (mm)10
- Metre (m)0.01
- Kilometre (km)0.00001
- Thou (mil) (thou)
One thousandth of an inch. Called a "mil" in US manufacturing, which is not a millimetre.
393.7008 - Inch (in)0.3937008
- Foot (ft)0.0328084
- Yard (yd)0.01093613
- Mile (mi)0.000006213712
- Nautical mile (nmi)
Exactly 1852 m by international agreement — longer than a statute mile.
0.000005399568 - Point (typographic) (pt)
The PostScript point: exactly 1/72 inch.
28.34646 - Pica (pc)2.362205
- CSS pixel (px)
A CSS reference pixel is 1/96 inch. It is a unit of layout, not of your screen’s hardware pixels.
37.79528 - Astronomical unit (au)6.684587e-14
- Light year (ly)1.057001e-18
- Parsec (pc)3.240779e-19
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How to use it
Enter a length and pick its unit to see it in centimetres, inches, feet, metres, miles, and every other unit at once, as you type.
Type a number and choose its unit. The answer appears in every other unit at once — centimetres, inches, feet, metres, kilometres, miles, and more.
The numbers are exact. Since 1959, an inch has been officially exactly 2.54 cm, so 6 feet is exactly 1.8288 metres — no rounding.
A few to watch out for: a nautical mile (used at sea and in the air) is about 15% longer than a normal mile. A “thou” is a thousandth of an inch, not a millimetre.
Centimetres to inches
An inch is exactly 2.54 cm, so divide centimetres by 2.54 to get inches. Here are the most common ones.
| Centimetres | Inches |
|---|---|
| 1 cm | 0.393701 in |
| 2 cm | 0.787402 in |
| 5 cm | 1.9685 in |
| 10 cm | 3.93701 in |
| 15 cm | 5.90551 in |
| 20 cm | 7.87402 in |
| 25 cm | 9.84252 in |
| 30 cm | 11.811 in |
| 50 cm | 19.685 in |
| 100 cm | 39.3701 in |
Feet to metres
A foot is exactly 0.3048 metres. Most people convert heights: 5 ft 10 in is 1.778 metres.
| Feet | Metres |
|---|---|
| 1 ft | 0.3048 m |
| 3 ft | 0.9144 m |
| 5 ft | 1.524 m |
| 5.5 ft | 1.6764 m |
| 6 ft | 1.8288 m |
| 6.5 ft | 1.9812 m |
| 10 ft | 3.048 m |
| 20 ft | 6.096 m |
| 50 ft | 15.24 m |
| 100 ft | 30.48 m |
Kilometres to miles
A kilometre is about 0.62 miles, so a 5 km run is just over 3 miles and a marathon is 26.2 miles. For miles to kilometres, multiply by 1.609.
| Kilometres | Miles |
|---|---|
| 1 km | 0.621371 mi |
| 5 km | 3.10686 mi |
| 10 km | 6.21371 mi |
| 21.0975 km | 13.1094 mi |
| 42.195 km | 26.2188 mi |
| 50 km | 31.0686 mi |
| 100 km | 62.1371 mi |
FAQ
How many centimetres are in an inch?
Exactly 2.54.
How do I convert feet and inches to centimetres?
Multiply the feet by 30.48 and the inches by 2.54, then add them. 5 ft 9 in is 175.26 cm.
Is a nautical mile the same as a mile?
No. A nautical mile is 1,852 metres — about 15% longer than a normal mile.
What is a “mil”?
In US engineering, a thousandth of an inch (0.0254 mm). It’s listed as “thou” so it isn’t confused with a millimetre.
How it worksFor the curious
Every unit is defined by its exact size in metres and each conversion goes through that base, so each constant is written once and every pair is derived from it rather than stored as a separate factor that could drift.
The 1959 international yard and pound agreement defines a yard as exactly 0.9144 m, making an inch exactly 25.4 mm and a mile exactly 1,609.344 m. Results are shown to seven significant figures.
A nautical mile is 1,852 m, defined as one minute of latitude. A CSS pixel is exactly 1/96 inch, a unit of layout rather than a hardware pixel.