Millimeter Calculator — mm to Inches, cm, Feet, Meters
Convert any length in millimeters to inches, centimeters, meters, micrometers, feet, yards and miles. All conversions use the exact international definitions — 1 mm = 1/25.4 inch and 1 mm = 0.001 m.
mm
Convert to
25,4 mm
- 1
Millimeters to in factor
1 mm = 0,0393700787 in = 0,0393700787 - 2
Multiply mm by factor
25,4 × 0,0393700787 = 1
Comment fonctionne cette calculatrice ?
Divide millimeters by 25.4 for inches, by 10 for centimeters, by 304.8 for feet, or by 1000 for meters. Multiply by 1000 for micrometers. All factors are exact international definitions — no approximation. Enter any mm length and pick a target unit for instant conversion.
Formule
How this is calculated
The millimeter is 1/1000 of a meter, the base unit of length in the SI system. Its relationship to the inch is exact: since 1 inch is defined as exactly 25.4 mm, dividing any millimeter value by 25.4 gives the exact inch equivalent with no rounding error. For feet, divide by 304.8 (since 1 ft = 12 in = 12 × 25.4 mm = 304.8 mm); for yards, divide by 914.4.
Millimeters are the standard precision unit across engineering, manufacturing and science. Fastener sizes, pipe diameters, sheet metal thickness, and screen bezels are all specified in mm. When working with very fine measurements (sub-millimeter), micrometers (µm, also called microns) are used — 1 mm = 1000 µm.
The reference table always shows the five most common targets so you can compare the same length across unit systems. For large distances, kilometers and miles are shown as well — though for those ranges the centimeter calculator or a dedicated distance converter is usually more practical.
Questions fréquentes
There are exactly 25.4 millimeters in one inch (defined in 1959). So 1 mm = 1/25.4 in ≈ 0.03937 in. To convert mm to inches, divide by 25.4; to go from inches to mm, multiply by 25.4.
Divide by 10: 1 mm = 0.1 cm. For example, 50 mm = 5 cm, 120 mm = 12 cm. The prefix "milli" means 1/1000 and "centi" means 1/100, so a centimeter is 10 times larger than a millimeter.
25.4 mm is exactly 1 inch — this is the definition. It is also the most useful conversion anchor: any mm measurement divided by 25.4 gives exact inches. For example, 50.8 mm = 2 in, 76.2 mm = 3 in.
Aussi appelé
TG we-Calculate Editorial Team. (2026). Millimeter Calculator — mm to Inches, cm, Feet, Meters [Online calculator]. TG we-Calculate. https://we-calculate.com/fr/calculator/millimeter-calculator
TG we-Calculate Editorial Team. "Millimeter Calculator — mm to Inches, cm, Feet, Meters." TG we-Calculate. 2026. https://we-calculate.com/fr/calculator/millimeter-calculator.
TG we-Calculate Editorial Team, "Millimeter Calculator — mm to Inches, cm, Feet, Meters," TG we-Calculate, 2026. [Online]. Available: https://we-calculate.com/fr/calculator/millimeter-calculator
@misc{wecalculate_millimeter_calculator, title = {Millimeter Calculator — mm to Inches, cm, Feet, Meters}, author = {{TG we-Calculate Editorial Team}}, howpublished = {\url{https://we-calculate.com/fr/calculator/millimeter-calculator}}, year = {2026}, note = {TG we-Calculate} }
Cette calculatrice vous a-t-elle aidé ?