How to convert millimeters to inches
1 in = 25.4 mm (exact)
inches = millimeters ÷ 25.4
1 mm ≈ 0.0393701 in
Shortcut: About 25 mm per inch: 100 mm ≈ 4 in (exactly 3.937 in).
Mm to inches table
| Millimeters | Inches |
|---|---|
| 1 mm | 0.0394 in |
| 2 mm | 0.0787 in |
| 3 mm | 0.1181 in |
| 4 mm | 0.1575 in |
| 5 mm | 0.1969 in |
| 6 mm | 0.2362 in |
| 8 mm | 0.315 in |
| 10 mm | 0.3937 in |
| 12 mm | 0.4724 in |
| 15 mm | 0.5906 in |
| 20 mm | 0.7874 in |
| 25 mm | 0.9843 in |
| 25.4 mm | 1 in |
| 30 mm | 1.1811 in |
| 40 mm | 1.5748 in |
| 50 mm | 1.9685 in |
| 75 mm | 2.9528 in |
| 100 mm | 3.937 in |
| 150 mm | 5.9055 in |
| 200 mm | 7.874 in |
| 300 mm | 11.811 in |
Values are calculated with exact factors and rounded for the table; the converter above shows full precision.
Worked examples
10 mm to inches
10 ÷ 25.4
0.3937 in
25.4 mm to inches
25.4 ÷ 25.4
1 in
300 mm to inches
300 ÷ 25.4
11.811 in
Questions
How many mm is an inch?
Exactly 25.4 millimeters.
How many inches is 10 mm?
About 0.3937 inches, a little over 3/8 inch.
How many inches is 300 mm?
About 11.811 inches, just under a foot.
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- Length & distance converter: every length & distance unit, with the full drawing
The history: Where the inch, foot, yard and mile came from.