Inches to Millimetres Converter
Type a value in inches to see it in millimetres. It works both ways: type in the millimetres box to convert back.
Formula
To convert inches to millimetres, multiply by 25.4.
1 in = 25.4 mm and 1 mm = 0.0393700787402 in.
Inches to millimetres table
| Inches | Millimetres |
|---|---|
| 1 in | 25.4 mm |
| 2 in | 50.8 mm |
| 3 in | 76.2 mm |
| 4 in | 101.6 mm |
| 5 in | 127 mm |
| 6 in | 152.4 mm |
| 8 in | 203.2 mm |
| 10 in | 254 mm |
| 12 in | 304.8 mm |
| 18 in | 457.2 mm |
| 24 in | 609.6 mm |
| 36 in | 914.4 mm |
| 60 in | 1,524 mm |
| 72 in | 1,828.8 mm |
Worked examples
2 in in millimetres
2 in
50.8 mm
2 × 25.4 = 50.8
10 in in millimetres
10 in
254 mm
10 × 25.4 = 254
60 in in millimetres
60 in
1,524 mm
60 × 25.4 = 1,524
About Inches to Millimetres Converter
This converter turns inches into millimetres as you type, and works the other way too: type in the millimetres box to convert back. To convert inches to millimetres, multiply by 25.4. For example, 2 in is 50.8 mm, and 10 in is 254 mm.
The UK uses metric units for most measurements, but road signs are in miles and yards, and many people still think of height in feet and inches, so length conversions come up every day. Both units have exact definitions, so the converter gives an exact result, rounded only for display. Use the table below for common values, or set the decimal places to round the answer for a form or a label.
How to use Inches to Millimetres Converter
- Type the amount in inches in the first box.
- Read the answer in millimetres in the second box and in the result line below.
- To convert the other way, type in the millimetres box instead, or use the swap button to open the millimetres to inches page.
- Choose a number of decimal places if you need a rounded figure, then copy the result line.
Common uses
- Following plans, patterns or instructions from abroad
- Converting a height or a distance for a form
- Helping with homework that mixes metric and imperial units
- Comparing running or cycling distances
Frequently asked questions
How many millimetres are in one inch?
There are 25.4 millimetres in one inch. This figure is exact, because both units have fixed definitions.
How do I convert inches to millimetres?
To convert inches to millimetres, multiply by 25.4. For example, 60 in is 1,524 mm.
How do I convert millimetres to inches?
Going the other way, divide by 25.4 (the same as multiplying by 0.03937007874). The millimetres to inches converter does this for you.
What is 24 in in millimetres?
24 in is 609.6 mm.
Why does the UK still use miles?
Road distances and speed limits stayed in miles and yards when the UK moved to metric units for trade and science. The Weights and Measures Act allows miles, yards, feet and inches for road traffic signs, so you will meet both systems.