The formula
To convert millimeters to inches, divide the millimeter value by 25.4. One inch equals exactly 25.4 millimeters. To convert inches to millimeters, multiply by 25.4.
Quick examples
- 10 mm ÷ 25.4 = 0.394 in
- 25.4 mm ÷ 25.4 = 1 in
- 58 mm ÷ 25.4 = 2.283 in
- 100 mm ÷ 25.4 = 3.937 in
Why it matters for layout
A small unit error changes the number of pieces that fit, the gap between designs and the final material estimate. Keep all dimensions in the same unit before calculating.
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