MM to CM Converter
Quick answer: To convert MM to CM, multiply by 0.1. For example, 10 mm is 1 cm. One millimeter equals 0.1 cm.
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Use the MM to CM Converter
MM to CM formula and what each symbol means
cm = mm × 0.1
| Symbol | Meaning |
|---|---|
| mm | Millimeter |
| cm | Centimeter |
MM to CM examples
1 mm
1 mm × 0.1 = 0.1 cm.
10 mm
10 mm × 0.1 = 1 cm.
100 mm
100 mm × 0.1 = 10 cm.
MM compared with CM
One cm is 10 times as large as one mm, so your number gets smaller when you convert MM to CM and bigger when you convert back. If the answer is not smaller than what you typed, you multiplied instead of dividing.
About MM and CM
Millimeter (mm): One thousandth of a metre. Centimeter (cm): One hundredth of a metre.
Where MM to CM conversions are used
Sports, aviation and shipping each keep their own favourites: yards on a football pitch, feet for altitude, nautical miles at sea. Road distances and maps use kilometres or miles, while building plans use metres, millimetres or feet.
How to calculate MM to CM step by step
- Enter the value in mm (the starting unit).
- Multiply by 0.1, because 1 mm = 0.1 cm.
- The product is the value in cm. To go back, divide by 0.1 or multiply by 10.
Popular length conversions
How to read your MM to CM result
Between metric and imperial, the key fact is that 1 inch is exactly 2.54 cm, which makes 1 foot exactly 0.3048 m, 1 yard exactly 0.9144 m and 1 mile exactly 1,609.344 m.
| MM | CM |
|---|---|
| 1 | 0.1 |
| 2 | 0.2 |
| 5 | 0.5 |
| 10 | 1 |
| 20 | 2 |
| 50 | 5 |
| 100 | 10 |
| 1,000 | 100 |
CM to MM: quick table
| CM | MM |
|---|---|
| 1 | 10 |
| 5 | 50 |
| 10 | 100 |
| 25 | 250 |
| 50 | 500 |
| 100 | 1,000 |
| 250 | 2,500 |
| 500 | 5,000 |
Common mistakes when calculating MM to CM
- Rounding the factor too early, for example using 2.5 instead of 2.54 for inches.
- Dividing when you should multiply: from mm to cm multiply by 0.1; from cm to mm divide by 0.1.
MM to CM FAQ
How many cm are in 1 mm?
1 mm equals 0.1 cm.
How many mm are in 1 cm?
1 cm equals 10 mm.
Is 1 mm = 0.1 cm an exact conversion?
Yes. The millimeter and the centimeter are both defined exactly in SI terms, so the ratio has no measurement uncertainty; 0.1 is just that ratio shown to 7 significant figures.
What is a centimeter (cm)?
One hundredth of a metre.
How can I estimate MM to CM in my head?
One cm is 10 times as large as one mm, so your number gets smaller when you convert MM to CM and bigger when you convert back. If the answer is not smaller than what you typed, you multiplied instead of dividing.
What is 150 mm in CM?
150 mm = 15 cm (since 150 × 0.1).
What is 0.5 mm in CM?
0.5 mm = 0.05 cm (since 0.5 × 0.1).
What is 25 mm in CM?
25 mm = 2.5 cm (since 25 × 0.1).
How many decimals should I keep when converting mm to cm?
Match the precision of your original measurement. For example, 1 cm rounds to 1 cm at 3 significant figures; keep more digits only for engineering or scientific work.
More in Length converters
- MM to KM Converter
- Miles to Meters Converter
- MM to Meters Converter
- Miles to KM Converter
- MM to Miles Converter
- Miles to Inches Converter
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Method, review and disclaimer
Edited by: Hemant Kumar and Anjita Rai, founders of ToolsVault (SEO and content professional, not a licensed adviser). Method: this tool runs in your browser using the formula shown on this page; the numbers you enter are not sent to our servers. Sources: NIST SP 811, Appendix B.8: conversion factors, BIPM: the SI base units