MM to Inches
Convert between millimeters and inches instantly.
Enter a length in millimeters to convert it to inches.
1 millimeter equals approximately 0.0393701 inches.
Use more decimals for product specs, drawings, and engineering checks.
Fractional inches are rounded approximations for practical use.
Converted inches
0.3937 in
10 mm = 0.3937 in
Original millimeters
10 mm
Input length.
Conversion factor
1 in = 25.4 mm
Exact definition.
Rounded fractional inch
25/64 in
Nearest 1/64 inch approximation.
Centimeters
1 cm
10 millimeters equal 1 centimeter.
Meters
0.01 m
1,000 millimeters equal 1 meter.
Reverse check
10 mm
Inches converted back to millimeters.
Local conversion
All calculations run instantly in your browser.
Decimal + fraction
Use decimal inches for precision and fractions for tape-measure estimates.
Precision friendly
Useful for product specs, engineering, DIY, and small measurements.
Dynamic Conversion Insights
What Millimeters and Inches Measure
Millimeters and inches both measure length, width, height, and distance.
Millimeters are small metric length units often used for product specs, tools, engineering, and small objects.
Inches are imperial and US customary units often used for screens, tools, construction, and US product dimensions.
Millimeters vs Inches Explained
Millimeters
10 millimeters equal 1 centimeter. Millimeters are smaller than inches and work well for precise measurements.
Inches
1 inch equals exactly 25.4 millimeters. 12 inches equal 1 foot.
Decimal Inches vs Fractional Inches
Decimal inches
Decimal inches are written like 0.375 in. They are common in engineering drawings, technical specs, and exact calculations.
Fractional inches
Fractional inches are written like 3/8 in. They are useful for tape measures, woodworking, and DIY, but rounded values should be treated as approximations.
Common mm to Inch Examples
| Millimeters | Decimal inches | Approx. fraction |
|---|---|---|
| 1 mm | 0.03937 in | 3/64 in |
| 2 mm | 0.07874 in | 5/64 in |
| 5 mm | 0.19685 in | 13/64 in |
| 10 mm | 0.3937 in | 25/64 in |
| 12.7 mm | 0.5 in | 1/2 in |
| 25.4 mm | 1 in | 1 in |
| 50 mm | 1.9685 in | 1 31/32 in |
| 100 mm | 3.93701 in | 3 15/16 in |
Engineering, DIY, and Product-Size Use Cases
Product dimensions
Bolts, screws, and hardware
Engineering drawings
3D printing
Woodworking and DIY
Screen and device dimensions
Jewelry and small measurements
Packaging and ecommerce specs
Formula Explanation
Inches = Millimeters ÷ 25.4
Millimeters = Inches × 25.4
Centimeters = Millimeters ÷ 10
Meters = Millimeters ÷ 1,000
Millimeters are the input value. The number 25.4 is the exact millimeter equivalent of one inch. Decimal inch results may be rounded for display. Fractional inches are rounded approximations when they do not match exactly.
Frequently Asked Questions
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