Millimeters to Inches (mm to in)
1 mm = 0.0393701 in
and 1 in = 25.4 mm
How to convert Millimeters to Inches
in = mm ÷ 25.4
To convert, divide the number of millimeters by 25.4. Example: 10 mm ÷ 25.4 = 0.393701 in.
1 inch is exactly 25.4 mm, so 1 mm = 1 ÷ 25.4 ≈ 0.03937 inches.
Comes up with drill bits, bolts, rainfall, jewellery and camera or phone specs that are measured in millimeters.
Mental shortcut: divide by 25 (overestimates by about 1.6%).
Millimeters to Inches conversion chart
| 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 |
| 7 mm | 0.2756 in |
| 8 mm | 0.315 in |
| 9 mm | 0.3543 in |
| 10 mm | 0.3937 in |
| 11 mm | 0.4331 in |
| 12 mm | 0.4724 in |
| 13 mm | 0.5118 in |
| 14 mm | 0.5512 in |
| 15 mm | 0.5906 in |
| 16 mm | 0.6299 in |
| 17 mm | 0.6693 in |
| 18 mm | 0.7087 in |
| 19 mm | 0.748 in |
| 20 mm | 0.7874 in |
| 21 mm | 0.8268 in |
| 22 mm | 0.8661 in |
| 23 mm | 0.9055 in |
| 24 mm | 0.9449 in |
| 25 mm | 0.9843 in |
| 26 mm | 1.02 in |
| 27 mm | 1.06 in |
| 28 mm | 1.1 in |
| 29 mm | 1.14 in |
| 30 mm | 1.18 in |
| 35 mm | 1.38 in |
| 40 mm | 1.57 in |
| Millimeters | Inches |
|---|---|
| 45 mm | 1.77 in |
| 50 mm | 1.97 in |
| 55 mm | 2.17 in |
| 60 mm | 2.36 in |
| 65 mm | 2.56 in |
| 70 mm | 2.76 in |
| 75 mm | 2.95 in |
| 80 mm | 3.15 in |
| 85 mm | 3.35 in |
| 90 mm | 3.54 in |
| 95 mm | 3.74 in |
| 100 mm | 3.94 in |
| 110 mm | 4.33 in |
| 120 mm | 4.72 in |
| 130 mm | 5.12 in |
| 140 mm | 5.51 in |
| 150 mm | 5.91 in |
| 160 mm | 6.3 in |
| 170 mm | 6.69 in |
| 180 mm | 7.09 in |
| 190 mm | 7.48 in |
| 200 mm | 7.87 in |
| 210 mm | 8.27 in |
| 220 mm | 8.66 in |
| 230 mm | 9.06 in |
| 240 mm | 9.45 in |
| 250 mm | 9.84 in |
| 260 mm | 10.24 in |
| 270 mm | 10.63 in |
| 280 mm | 11.02 in |
| 290 mm | 11.42 in |
| 300 mm | 11.81 in |
Values rounded to 2 decimal places (4 below 1). Use the converter above for more precision.
Frequently asked questions
How many inches are in 1 millimeter?
1 millimeter = 0.0393701 inches. 1 inch is exactly 25.4 mm, so 1 mm = 1 ÷ 25.4 ≈ 0.03937 inches.
How do I convert millimeters to inches?
Divide the number of millimeters by 25.4. Example: 10 mm ÷ 25.4 = 0.393701 in.
Is there a quick way to estimate mm to in in your head?
Yes — divide by 25. This overestimates by about 1.6%. Use the exact formula (in = mm ÷ 25.4) when precision matters.
How do I convert inches back to millimeters?
Use mm = in × 25.4 — multiply the number of inches by 25.4. See the Inches to Millimeters page for a full chart.