MM to Inches Calculator
Enter millimeters to get decimal inches, fractional inches, centimeters, and meters.
The formula
Inches = millimeters ÷ 25.4. The factor is exact by international definition, fixed in 1959, not a rounded approximation.
Centimeters = millimeters ÷ 10. Meters = millimeters ÷ 1000. Both follow directly from the metric system's base-10 structure, unlike the inch-to-foot (12) or foot-to-yard (3) relationships in the imperial system.
mm to inches chart (1 to 30 mm)
Every whole millimeter from 1 to 30, with the decimal inch value and the nearest sixteenth-inch fraction.
| mm | Decimal inches | Nearest 1/16 |
|---|---|---|
| 1 mm | 0.03937" | 1/16" |
| 2 mm | 0.07874" | 1/16" |
| 3 mm | 0.11811" | 1/8" |
| 4 mm | 0.15748" | 3/16" |
| 5 mm | 0.19685" | 3/16" |
| 6 mm | 0.23622" | 1/4" |
| 7 mm | 0.275591" | 1/4" |
| 8 mm | 0.314961" | 5/16" |
| 9 mm | 0.354331" | 3/8" |
| 10 mm | 0.393701" | 3/8" |
| 11 mm | 0.433071" | 7/16" |
| 12 mm | 0.472441" | 1/2" |
| 13 mm | 0.511811" | 1/2" |
| 14 mm | 0.551181" | 9/16" |
| 15 mm | 0.590551" | 9/16" |
| 16 mm | 0.629921" | 5/8" |
| 17 mm | 0.669291" | 11/16" |
| 18 mm | 0.708661" | 11/16" |
| 19 mm | 0.748031" | 3/4" |
| 20 mm | 0.787402" | 13/16" |
| 21 mm | 0.826772" | 13/16" |
| 22 mm | 0.866142" | 7/8" |
| 23 mm | 0.905512" | 7/8" |
| 24 mm | 0.944882" | 15/16" |
| 25 mm | 0.984252" | 1" |
| 26 mm | 1.023622" | 1" |
| 27 mm | 1.062992" | 1 1/16" |
| 28 mm | 1.102362" | 1 1/8" |
| 29 mm | 1.141732" | 1 1/8" |
| 30 mm | 1.181102" | 1 3/16" |
Common metric sizes
3 mm is close to 1/8". 6 mm is close to 1/4". 10 mm is close to 3/8". 13 mm is close to 1/2". 19 mm is close to 3/4". 25 mm is close to 1", though none of these pairs are exact matches; the exact values are in the table above.
Related mm and metric conversions
Need the reverse direction, from inches to millimeters? Use the Inches to MM Calculator. To compare a single mm value across all four fractional precisions at once, use the MM to Fraction Inch Converter. For centimeters or meters instead of millimeters, use the Metric to Imperial Converter.
Individual Millimeter Answers
Frequently Asked Questions
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