Millimeters to Centimeters converter (mm → cm)
9 mm = 0.9000 cm. 1 mm = 0.1000 cm. Type any value below for an instant answer, or find your number in the conversion chart.
mm to cm formula
Worked example: 5 mm = 0.5000 cm. The defining value behind this factor is documented on our length & distance standards page.
Millimeters to Centimeters chart
Includes standard reference values plus the specific numbers people search for most.
| Millimeters (mm) | Centimeters (cm) |
|---|---|
| 1 mm | 0.1000 cm |
| 2 mm | 0.2000 cm |
| 3 mm | 0.3000 cm |
| 4 mm | 0.4000 cm |
| 5 mm | 0.5000 cm |
| 6 mm | 0.6000 cm |
| 7 mm | 0.7000 cm |
| 8 mm | 0.8000 cm |
| 9 mm | 0.9000 cm |
| 10 mm | 1 cm |
| 12 mm | 1.2 cm |
| 15 mm | 1.5 cm |
| 20 mm | 2 cm |
| 22 mm | 2.2 cm |
| 24 mm | 2.4 cm |
| 25 mm | 2.5 cm |
| 28 mm | 2.8 cm |
| 30 mm | 3 cm |
| 35 mm | 3.5 cm |
| 40 mm | 4 cm |
| 45 mm | 4.5 cm |
| 50 mm | 5 cm |
| 55 mm | 5.5 cm |
| 75 mm | 7.5 cm |
| 80 mm | 8 cm |
| 90 mm | 9 cm |
| 100 mm | 10 cm |
| 150 mm | 15 cm |
| 200 mm | 20 cm |
| 250 mm | 25 cm |
| 500 mm | 50 cm |
| 900 mm | 90 cm |
| 1000 mm | 100 cm |
Most-searched mm to cm answers
5 mm to cm
0.5000 cm10 mm to cm
1 cm9 mm to cm
0.9000 cm900 mm to cm
90 cm1 mm to cm
0.1000 cm100 mm to cm
10 cm30 mm to cm
3 cm150 mm to cm
15 cm3 mm to cm
0.3000 cm50 mm to cm
5 cm7 mm to cm
0.7000 cm8 mm to cm
0.8000 cmWhen to convert mm to cm
Use millimeters to centimeters for drawings, product dimensions, crafts and small measurements.
- ▸Simplify a millimeter specification into centimeters.
- ▸Compare technical dimensions with a centimeter ruler.
Common mistakes
- ✕Ten millimeters equal exactly one centimeter, so divide by 10 without rounding.
- ✕Mixing US and international inches — since 1959 all inches are 25.4 mm exactly; older US "survey foot" values are slightly different.
- ✕Off-by-decimal errors: 1 cm = 10 mm, 1 m = 100 cm — a misplaced decimal turns a mm into a wildly wrong cm.
- ✕Confusing feet with yards (1 yd = 3 ft) in DIY calculations.
- ✕The US survey foot is not the international foot. The US survey foot was 1200/3937 m (about 0.30480061 m) — roughly 2 parts per million longer than the international foot of 0.3048 m. NIST retired it for new work at the end of 2022, but old survey and land records still use it. Over a mile the difference is about 3 mm; over 100 km it is about 200 mm, which matters in surveying and geodesy and nowhere else.
Regional usage & source
Metric units (mm, cm, m, km) are used in most of the world. Imperial units (in, ft, yd, mi) are standard in the US and still common in the UK for road distances and human height.
Reference: Conversion factors are defined by the International System of Units (SI) as maintained by the BIPM (bipm.org) and NIST (nist.gov). 1 inch = exactly 0.0254 meters (international yard and pound agreement, 1959).
How these numbers are produced and rounded: methodology.