How to use the cm to meters converter
- Type a length in the Centimeters field to get meters, or in the Meters field to get centimeters.
- Clear the field you are not using. The page starts with 100 in the centimeters box, so empty it before typing in the meters box.
- Read both values in the result rows. The meters row is always listed first, then the centimeters row.
- Negative numbers keep their sign, which helps with offsets and coordinates.
The factor and where it comes from
The prefix centi stands for 10-2. The BIPM SI Brochure (9th edition, 2019, with the 2022 update) and NIST SP 811 (Guide for the Use of the International System of Units, 2008 edition) both list it, which makes 1 cm = 0.01 m an exact definition and not a measured value.
That is why a cm to m conversion never needs a lookup table or a rounding rule, only a shift of the decimal point.
Centimeters to meters: m = cm / 100. Meters to centimeters: cm = m x 100. In decimal notation the point moves two places, left for cm to m and right for m to cm.
Worked examples from the tool
These rows were produced by the converter itself.
| You enter | Meters | Centimeters |
|---|---|---|
| 170 cm | 1.7 | 170 |
| 4.5 m | 4.5 | 450 |
| 0.1 cm | 0.001 | 0.1 |
| 0.07 m | 0.07 | 7 |
| -30 cm | -0.3 | -30 |
| 1015 cm | 10,000,000,000,000 | 1,000,000,000,000,000 |
The 0.07 m row shows why output is rounded. In plain double-precision arithmetic 0.07 * 100 evaluates to 7.000000000000001. The tool rounds to 12 significant digits, so you see 7.
Edge cases and rounding
- Zero converts to 0 in both rows.
- Results keep up to 12 significant digits. Numbers with magnitude below 1e-9 are shown in exponent form, so 1e-8 cm becomes
1e-10m and 1e-12 m becomes1e-10cm. - Both fields filled returns an error, because the direction is unknown. Both fields empty returns an error as well.
- Text such as
abcis rejected. A decimal comma such as1,5is rejected too, so type 1.5. - There is no fixed input limit: any finite number converts, and magnitudes of 1e21 or more are written in exponent form. If the converted value no longer fits in a double (about 1.8e308), the tool says the number is too large.
Choosing between cm and m
A person who is 1.70 m tall is 170 cm tall. A 2.4 m ceiling is 240 cm, and a 215 cm sofa fits a 2.5 m wall with 35 cm to spare. Furniture, clothing and medical records usually use centimeters. Rooms, building plans and running tracks use meters. When a figure passes about 300 cm, most people switch to meters because 3.2 m is easier to read than 320 cm. A tailor writing a 96 cm chest or a doctor recording 175 cm of height stays in centimeters, because the whole number needs no decimal point.
For millimeters use cm to mm. For imperial lengths use cm to inches or cm to feet.
Neighbouring metric lengths
Every metric step below is a power of ten, so the same decimal shift applies.
| Unit | Value in meters |
|---|---|
| 1 kilometer | 1000 |
| 1 decimeter | 0.1 |
| 1 centimeter | 0.01 |
| 1 millimeter | 0.001 |
To reach yards from meters, use meters to yards. For long distances there is miles to meters.
Worked examples
| Example | Input | Result |
|---|---|---|
| Average human height | Centimeters (cm): 170 | Meters: 1.7; Centimeters: 170 |
| Room length | Meters (m): 4.5 | Meters: 4.5; Centimeters: 450 |
| A4 paper width | Centimeters (cm): 21 | Meters: 0.21; Centimeters: 21 |
| Zero | Centimeters (cm): 0 | Meters: 0; Centimeters: 0 |
FAQ
How do I convert cm to m?
Divide the centimeters by 100. For example 250 cm / 100 = 2.5 m.
How many centimeters are in a meter?
Exactly 100. The prefix centi means one hundredth, so the factor is a definition and has no rounding error. A 2 m rope is 200 cm and a 0.35 m shelf is 35 cm.
Why do I see 1e-10 instead of 0.0000000001?
Results smaller than 1e-9 in magnitude, or 1e21 and larger, are written in exponent form. For example 1e-8 cm gives 1e-10 m.
Why does the tool show an error when both boxes contain numbers?
It cannot tell which value is the source. Clear one box and the conversion runs.
Can I type 1,5 for 1.5?
No. The input expects a decimal point. A comma is rejected with an invalid number message.
Is the answer rounded?
It is rounded to 12 significant digits. That removes floating point noise such as 7.000000000000001 for 0.07 m in cm, and leaves every ordinary length exact.
What happens with negative lengths?
The sign is preserved. -30 cm gives -0.3 m.