Millimetres to miles, and everything in between
Type a length and read it in any other unit — inches to centimetres, metres to feet, kilometres to miles, and the nautical mile that belongs to neither system. The answer updates on every keystroke, and the tables underneath cover the conversions people look up most, so you can check a figure without typing anything at all. Nothing is uploaded or saved.
- Nothing is uploaded or saved
- Works offline
Length converter
Inch to Centimetre
2.54cm
1 in = 2.54 cm
1 in = 2.54 cm
1 cm = 0.393700787402 in
The inch is defined as exactly 25.4 mm, so every imperial length here is exact rather than approximate.
The same amount in every unit
Common length conversions
Every figure below is produced by the same conversion code as the calculator above, so the two can never disagree.
Inches to centimetres
| Inch (in) | Centimetre (cm) | Millimetre (mm) |
|---|---|---|
| 1 | 2.54 | 25.4 |
| 2 | 5.08 | 50.8 |
| 3 | 7.62 | 76.2 |
| 4 | 10.16 | 101.6 |
| 5 | 12.7 | 127 |
| 6 | 15.24 | 152.4 |
| 7 | 17.78 | 177.8 |
| 8 | 20.32 | 203.2 |
| 9 | 22.86 | 228.6 |
| 10 | 25.4 | 254 |
| 11 | 27.94 | 279.4 |
| 12 | 30.48 | 304.8 |
The inch is defined as exactly 25.4 mm, so every imperial length here is exact rather than approximate.
Feet to metres
| Foot (ft) | Metre (m) | Centimetre (cm) |
|---|---|---|
| 1 | 0.3048 | 30.48 |
| 2 | 0.6096 | 60.96 |
| 3 | 0.9144 | 91.44 |
| 4 | 1.2192 | 121.92 |
| 5 | 1.524 | 152.4 |
| 6 | 1.8288 | 182.88 |
| 7 | 2.1336 | 213.36 |
| 8 | 2.4384 | 243.84 |
| 9 | 2.7432 | 274.32 |
| 10 | 3.048 | 304.8 |
| 15 | 4.572 | 457.2 |
| 20 | 6.096 | 609.6 |
| 25 | 7.62 | 762 |
| 50 | 15.24 | 1,524 |
| 100 | 30.48 | 3,048 |
Kilometres to miles
| Kilometre (km) | Mile (mi) | Yard (yd) |
|---|---|---|
| 1 | 0.621371192237 | 1,093.61329834 |
| 2 | 1.24274238447 | 2,187.22659668 |
| 3 | 1.86411357671 | 3,280.83989501 |
| 4 | 2.48548476895 | 4,374.45319335 |
| 5 | 3.10685596119 | 5,468.06649169 |
| 10 | 6.21371192237 | 10,936.1329834 |
| 15 | 9.32056788356 | 16,404.1994751 |
| 20 | 12.4274238447 | 21,872.2659668 |
| 25 | 15.5342798059 | 27,340.3324584 |
| 30 | 18.6411357671 | 32,808.3989501 |
| 50 | 31.0685596119 | 54,680.6649169 |
| 75 | 46.6028394178 | 82,020.9973753 |
| 100 | 62.1371192237 | 109,361.329834 |
Metres to feet and inches
| Metre (m) | Foot (ft) | Inch (in) |
|---|---|---|
| 0.5 | 1.64041994751 | 19.6850393701 |
| 1 | 3.28083989501 | 39.3700787402 |
| 1.5 | 4.92125984252 | 59.0551181102 |
| 1.6 | 5.24934383202 | 62.9921259843 |
| 1.7 | 5.57742782152 | 66.9291338583 |
| 1.8 | 5.90551181102 | 70.8661417323 |
| 1.9 | 6.23359580052 | 74.8031496063 |
| 2 | 6.56167979003 | 78.7401574803 |
| 3 | 9.84251968504 | 118.11023622 |
| 5 | 16.4041994751 | 196.850393701 |
| 10 | 32.8083989501 | 393.700787402 |
| 25 | 82.0209973753 | 984.251968504 |
| 50 | 164.041994751 | 1,968.50393701 |
| 100 | 328.083989501 | 3,937.00787402 |
The inch is defined as exactly 25.4 mm, so every imperial length here is exact rather than approximate.
How it works
- 1
Type the length
Enter the number and pick the unit beside it. There is no Convert button: the result recalculates on every keystroke, which is the whole reason to open a web page instead of reaching for a printed table.
- 2
Choose what you want it in
Metric and imperial units share one list, so millimetres to inches takes exactly the same two taps as millimetres to metres. The panel on the right also shows the same length in every other unit at once, which is quicker than converting three times.
- 3
Swap the direction
The swap button exchanges the two units and keeps the number you typed. It deliberately does not push the rounded result back into the input: that would replace your exact figure with a rounded one, and swapping twice would no longer return you to where you started.
- 4
Check it against the tables
Inches to centimetres, feet to metres, kilometres to miles. Every cell is generated by the same code that answers the field above, so the table and the calculator cannot disagree — which is the failure mode of every converter that types its reference table out by hand.
Frequently asked questions
How many centimetres are in an inch?
Exactly 2.54. That is not a measurement anyone made — since the international yard and pound agreement of 1959 the inch has been defined as exactly 25.4 millimetres, which makes a foot exactly 30.48 cm, a yard exactly 0.9144 m and a mile exactly 1,609.344 m. Every imperial length on this page comes from that single definition, so the conversions are exact rather than rounded.
Why does a nautical mile exist when there is already a mile?
Because it measures something different. A nautical mile is one minute of latitude — one sixtieth of a degree measured along a meridian — so a navigator with a paper chart can read distance straight off the latitude scale printed down the side, with no conversion and no table. That made it the natural unit at sea, and aviation inherited it along with the charts. It is now fixed at exactly 1,852 metres, which is about 15% longer than the statute mile of 1,609.344 m. One nautical mile per hour is a knot.
How much longer is a metre than a yard?
A yard is 0.9144 m, so a metre is about 9.4% longer. On a running track that difference is the whole story: 100 m is a little over 109 yards, which is why records set over 100 yards do not line up with metric ones and why the two were never quietly treated as the same distance.
Converting 1 mm to miles gives a tiny number. Is that right?
Yes — one millimetre is 0.000000621371 miles. Results are kept to twelve significant figures rather than to a fixed number of decimal places, precisely so that answers this small survive. Rounding to two decimals would display that conversion as 0, and a converter that confidently answers zero is worse than one that answers nothing.
Can I enter a length as feet and inches together, like 5′ 9″?
Not as one entry, and that is on purpose. Convert to a single unit first: 5 feet 9 inches is 69 inches, which the field takes happily. A box that accepts both notations has to guess, and 5.9 feet and 5 feet 9 inches are different lengths — 5 ft 9 in is 5.75 feet. A field that silently picks one of those for you is a field that is sometimes wrong without saying so.
Which units does this cover?
Millimetres, centimetres, metres and kilometres on the metric side; inches, feet, yards and miles on the imperial side; and the nautical mile. Microns, thousandths of an inch, furlongs and light years are left out because a list long enough to include them is a list nobody can scan — these nine cover almost everything anyone actually needs to convert.
Is anything I type uploaded or saved?
No. The arithmetic runs in your own browser, there is no server behind this site to upload anything to, and this page writes nothing to your device — no history, no saved values. Close the tab and the figures are gone.