How to use it
Type the millimeters in the Metric mm box. The Inches box fills in with the decimal, and the answer shows the nearest fraction you would find on a tape measure. The other boxes give the same length as feet and inches and as decimal feet.
The fraction is rounded to the nearest 1/16 inch and marked with ≈ when rounding changed it. For small parts, change Round to, beside the results, to 1/32" or 1/64".
To go from inches to millimeters, type in the Inches box, such as 3 1/2, and read the Metric mm box. Centimeters and meters work in the mm box if you add the unit: 10cm or 1.2m.
The math
- Millimeters to inches: divide by 25.4. 100 ÷ 25.4 = 3.937 inches.
- Decimal inches to a fraction: multiply the part after the decimal point by 16 and round. For 3.937, 0.937 × 16 = 14.99, which rounds to 15 sixteenths, so 100 mm is ≈ 3 15/16".
- Inches to millimeters: multiply by 25.4. 3 1/2 inches is 3.5 × 25.4 = 88.9 mm.
One inch is exactly 25.4 mm, so 1 mm is 0.0394 inches. For lengths over a foot, the inches to feet converter has a chart.
mm to inches chart, 1 to 25 mm
Fractions here are rounded to the nearest 1/64 inch.
| Millimeters | Inches | Nearest 1/64" |
|---|---|---|
| 1 mm | 0.0394 in | ≈ 3/64" |
| 2 mm | 0.0787 in | ≈ 5/64" |
| 3 mm | 0.1181 in | ≈ 1/8" |
| 4 mm | 0.1575 in | ≈ 5/32" |
| 5 mm | 0.1969 in | ≈ 13/64" |
| 6 mm | 0.2362 in | ≈ 15/64" |
| 7 mm | 0.2756 in | ≈ 9/32" |
| 8 mm | 0.315 in | ≈ 5/16" |
| 9 mm | 0.3543 in | ≈ 23/64" |
| 10 mm | 0.3937 in | ≈ 25/64" |
| 11 mm | 0.4331 in | ≈ 7/16" |
| 12 mm | 0.4724 in | ≈ 15/32" |
| 13 mm | 0.5118 in | ≈ 33/64" |
| 14 mm | 0.5512 in | ≈ 35/64" |
| 15 mm | 0.5906 in | ≈ 19/32" |
| 16 mm | 0.6299 in | ≈ 5/8" |
| 17 mm | 0.6693 in | ≈ 43/64" |
| 18 mm | 0.7087 in | ≈ 45/64" |
| 19 mm | 0.748 in | ≈ 3/4" |
| 20 mm | 0.7874 in | ≈ 25/32" |
| 21 mm | 0.8268 in | ≈ 53/64" |
| 22 mm | 0.8661 in | ≈ 55/64" |
| 23 mm | 0.9055 in | ≈ 29/32" |
| 24 mm | 0.9449 in | ≈ 15/16" |
| 25 mm | 0.9843 in | ≈ 63/64" |
mm to inches chart, 30 to 3000 mm
Feet and inches here are rounded to the nearest 1/16 inch.
| Millimeters | Inches | Feet and inches |
|---|---|---|
| 30 mm | 1.1811 in | ≈ 1 3/16" |
| 40 mm | 1.5748 in | ≈ 1 9/16" |
| 50 mm | 1.9685 in | ≈ 1 15/16" |
| 60 mm | 2.3622 in | ≈ 2 3/8" |
| 75 mm | 2.9528 in | ≈ 2 15/16" |
| 100 mm | 3.937 in | ≈ 3 15/16" |
| 150 mm | 5.9055 in | ≈ 5 7/8" |
| 200 mm | 7.874 in | ≈ 7 7/8" |
| 250 mm | 9.8425 in | ≈ 9 13/16" |
| 300 mm | 11.811 in | ≈ 11 13/16" |
| 400 mm | 15.748 in | ≈ 1' 3 3/4" |
| 500 mm | 19.685 in | ≈ 1' 7 11/16" |
| 600 mm | 23.622 in | ≈ 1' 11 5/8" |
| 900 mm | 35.4331 in | ≈ 2' 11 7/16" |
| 1000 mm | 39.3701 in | ≈ 3' 3 3/8" |
| 1200 mm | 47.2441 in | ≈ 3' 11 1/4" |
| 1500 mm | 59.0551 in | ≈ 4' 11 1/16" |
| 2000 mm | 78.7402 in | ≈ 6' 6 3/4" |
| 2400 mm | 94.4882 in | ≈ 7' 10 1/2" |
| 3000 mm | 118.1102 in | ≈ 9' 10 1/8" |
Fractions of an inch in mm
| Fraction | Decimal inches | Millimeters |
|---|---|---|
| 1/16" | 0.0625 in | 1.5875 mm |
| 1/8" | 0.125 in | 3.175 mm |
| 3/16" | 0.1875 in | 4.7625 mm |
| 1/4" | 0.25 in | 6.35 mm |
| 5/16" | 0.3125 in | 7.9375 mm |
| 3/8" | 0.375 in | 9.525 mm |
| 7/16" | 0.4375 in | 11.1125 mm |
| 1/2" | 0.5 in | 12.7 mm |
| 9/16" | 0.5625 in | 14.2875 mm |
| 5/8" | 0.625 in | 15.875 mm |
| 11/16" | 0.6875 in | 17.4625 mm |
| 3/4" | 0.75 in | 19.05 mm |
| 13/16" | 0.8125 in | 20.6375 mm |
| 7/8" | 0.875 in | 22.225 mm |
| 15/16" | 0.9375 in | 23.8125 mm |
| 1" | 1 in | 25.4 mm |
Questions
How do I convert mm to inches?
Divide the millimeters by 25.4. 100 mm ÷ 25.4 is 3.937 inches, which is about 3 15/16" on a tape measure.
How many mm are in an inch?
Exactly 25.4. Half an inch is 12.7 mm and a quarter inch is 6.35 mm.
How many inches is 10 mm?
10 mm is 0.3937 inches, which is about 25/64" to the nearest 1/64 inch.
How many inches is 300 mm?
300 mm is 11.811 inches, which is about 11 13/16". It is a little short of a foot, which is 304.8 mm.
How do I convert inches to mm?
Multiply the inches by 25.4. 3 1/2 inches is 3.5 × 25.4 = 88.9 mm. In the converter, type 3 1/2 in the Inches box.
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