How many millimeters are in 1 centimeter?

1 cm equals 10 mm. This is an exact conversion factor defined by NIST.

How do I convert centimeters to millimeters?

Multiply the value in cm by the conversion factor. For example, 10 cm = 100 mm. Use our calculator above for instant results.

Is the centimeters to millimeters conversion exact?

Yes, this conversion is mathematically exact based on the international definition of these units (NIST SP 811).

Can I convert centimeters to millimeters offline?

Yes! OmniConvert runs entirely in your browser — no internet connection needed after the page loads. Your data never leaves your device, ensuring complete privacy.

What is the difference between centimeters and millimeters?

Centimeters (cm) and Millimeters (mm) are both units of length but belong to different measurement systems. 1 cm = 10 mm. Use the converter above to switch between them instantly.

Centimeters to Millimeters (cm → mm) — Free Online Converter

cm → mm Reference Table

cm	mm
0.001 cm	0.01 mm
0.002 cm	0.02 mm
0.003 cm	0.03 mm
0.004 cm	0.04 mm
0.005 cm	0.05 mm
0.006 cm	0.06 mm
0.007 cm	0.07 mm
0.008 cm	0.08 mm
0.009 cm	0.09 mm
0.01 cm	0.1 mm
0.02 cm	0.2 mm
0.03 cm	0.3 mm
0.04 cm	0.4 mm
0.05 cm	0.5 mm
0.06 cm	0.6 mm
0.07 cm	0.7 mm
0.08 cm	0.8 mm
0.09 cm	0.9 mm
0.1 cm	1 mm
0.2 cm	2 mm
0.3 cm	3 mm
0.4 cm	4 mm
0.5 cm	5 mm
0.6 cm	6 mm
0.7 cm	7 mm
0.8 cm	8 mm
0.9 cm	9 mm
1 cm	10 mm
1.5 cm	15 mm
2 cm	20 mm
2.5 cm	25 mm
3 cm	30 mm
3.5 cm	35 mm
4 cm	40 mm
4.5 cm	45 mm
5 cm	50 mm
5.5 cm	55 mm
6 cm	60 mm
6.5 cm	65 mm
7 cm	70 mm
7.5 cm	75 mm
8 cm	80 mm
8.5 cm	85 mm
9 cm	90 mm
9.5 cm	95 mm
10 cm	100 mm
11 cm	110 mm
12 cm	120 mm
13 cm	130 mm
14 cm	140 mm
15 cm	150 mm
16 cm	160 mm
17 cm	170 mm
18 cm	180 mm
19 cm	190 mm
20 cm	200 mm
25 cm	250 mm
30 cm	300 mm
35 cm	350 mm
40 cm	400 mm
45 cm	450 mm
50 cm	500 mm
55 cm	550 mm
60 cm	600 mm
65 cm	650 mm
70 cm	700 mm
75 cm	750 mm
80 cm	800 mm
85 cm	850 mm
90 cm	900 mm
95 cm	950 mm
100 cm	1000 mm
120 cm	1200 mm
125 cm	1250 mm
130 cm	1300 mm
140 cm	1400 mm
150 cm	1500 mm
160 cm	1600 mm
175 cm	1750 mm
180 cm	1800 mm
200 cm	2000 mm
225 cm	2250 mm
250 cm	2500 mm
275 cm	2750 mm
300 cm	3000 mm
350 cm	3500 mm
400 cm	4000 mm
450 cm	4500 mm
500 cm	5000 mm
600 cm	6000 mm
700 cm	7000 mm
750 cm	7500 mm
800 cm	8000 mm
900 cm	9000 mm
1000 cm	10000 mm
1200 cm	12000 mm
1250 cm	12500 mm
1500 cm	15000 mm
1750 cm	17500 mm
2000 cm	20000 mm
2500 cm	25000 mm
3000 cm	30000 mm
4000 cm	40000 mm
4500 cm	45000 mm
5000 cm	50000 mm
6000 cm	60000 mm
7000 cm	70000 mm
7500 cm	75000 mm
8000 cm	80000 mm
9000 cm	90000 mm
10000 cm	100000 mm
15000 cm	150000 mm
20000 cm	200000 mm
25000 cm	250000 mm
50000 cm	500000 mm
75000 cm	750000 mm
100000 cm	1000000 mm

Values based on NIST SP 811 conversion factors

Why Convert Centimeters to Millimeters?

Converting between centimeters (cm) and millimeters (mm) is one of the most common length conversions. Whether for engineering, cooking, travel, or science, knowing how to quickly convert cm to mm saves time and prevents errors.

Length conversions between cm and mm are fundamental in construction, manufacturing, and international trade. Architects rely on precise conversions when adapting building plans between metric and imperial standards — a 1% error on a 30-meter wall translates to 30 cm of misalignment. Travelers frequently convert between kilometers and miles for road trips, while online shoppers need length conversions to verify clothing sizes, furniture dimensions, and screen diagonals across international retailers. In athletics, track distances (100m, 1500m, marathon) must be precisely converted for record comparisons across different measurement traditions.

How to Convert Centimeters to Millimeters

To convert centimeters to millimeters, use the following formula:

mm = cm × 10

Example: 1 cm = 10 mm

For example, 5 cm = 50 mm, 10 cm = 100 mm, and 100 cm = 1000 mm. For larger values, 1000 cm = 10000 mm. Conversely, 1 mm = 0.1 cm. Our calculator above performs this conversion instantly with full precision — no rounding errors.

Common Mistakes to Avoid

Confusing similar units: confusing nautical miles with regular miles, or yards with meters.
Decimal errors: moving the decimal point the wrong way (e.g., 100 cm = 1 m, not 10 m).
Approximation: assuming an inch is exactly 2.5 cm (it's 2.54 cm).

Pro Tips

Use 'approx' for mental math: 1 km is roughly 0.6 miles (or 2/3 for quick estimates).
Visualize: A meter is about a guitar length; an inch is a thumb width.
Ruler check: Most rulers show cm and inches together—great for quick checks.

What is a Centimeter?

The centimeter (cm) is a metric unit of length equal to one-hundredth of a meter (0.01 m). It is part of the International System of Units (SI) and is defined based on the meter.

Centimeters are commonly used worldwide for everyday measurements where meters are too large, such as human height, furniture dimensions, and textile measurements.

What is a Millimeter?

The millimeter (mm) is a metric unit of length equal to one-thousandth of a meter (0.001 m). It is a standard unit in the International System of Units (SI).

Millimeters are used for precision engineering, manufacturing dimensions, rainfall measurement, and paper sizes (ISO 216). It represents small scale accuracy.

Centimeters → Millimeters

Centimeters to Millimeters Formula