Authoritative definitions of the International System of Units and SI prefixes.
Unit conversion
Centimetres to Kilometres Converter
1 cm = 0.00001 km. Enter a value to convert cm to km, then use the formula and table below. Displayed digits may be rounded.
Length & distanceInstant result
Decimals
Formula result = input × 0.01 ÷ 1000. 1 cm = 1.00000e-5 km
Nonzero results too small for the selected decimal places use scientific notation.
Nonzero results too small for the selected decimal places use scientific notation.
Common examples
One value, several units
Metres0.01 m
Kilometres1.00000e-5 km
Millimetres10 mm
Miles6.21371e-6 mi
Yards0.0109 yd
Feet0.0328 ft
Inches0.3937 in
Nautical miles5.39957e-6 nmi
Conversion table
| cm | km |
|---|---|
| 1 cm | 1.00000e-5 km |
| 2 cm | 2.00000e-5 km |
| 5 cm | 0.0001 km |
| 10 cm | 0.0001 km |
| 25 cm | 0.0003 km |
| 50 cm | 0.0005 km |
| 100 cm | 0.001 km |
Conversion chart
1 cm1.00000e-5 km
5 cm0.0001 km
10 cm0.0001 km
25 cm0.0003 km
50 cm0.0005 km
Worked example
1 cm = 0.00001 km. Apply the selected conversion formula to other input values.
Unit definition
Centimetres (cm) One centimetres equals 0.01 metre.
Unit history
Centimetres is represented here using its modern SI definition or an internationally accepted relationship to an SI base unit.
Step by step
1. Parse the value, including fractions.
2. Convert cm to metre.
3. Convert the base value to km and apply your display precision.
Understand the result before using it
Centimetres to Kilometres converts a value measured in Centimetres (cm) into the equivalent value in Kilometres (km). The numerical value changes because the size and definition of the selected unit changes; the underlying quantity does not.
Calculated result
The conversion follows the displayed unit relationship. Display rounding can hide additional digits, and measured inputs cannot become more accurate merely by changing units.
Formula, assumptions, and example
Formula
result = input × 0.01 ÷ 1000
Assumptions
- Centimetres and Kilometres represent the same length & distance quantity.
- The input is expressed in cm; the output is expressed in km.
- The unit definitions and conventional relationship shown on this page apply.
Worked example
1 cm = 0.00001 km. For another value, apply the same relationship and round only to the precision your source measurement supports.
When to use it
Good uses
- Read a cm measurement in a document that expects km.
- Compare a centimetres value with a value reported in kilometres.
- Check the cm to km arithmetic before copying the result into another calculation.
Limitations
Common mistakes to avoid
- Do not confuse cm with another unit that has a similar name or symbol.
- Round the output to a precision justified by the original measurement.
- Verify safety-critical, regulated, laboratory, and contractual conversions against the controlling standard.
Sources and further reading
These references explain the underlying standards or provide authoritative context. Your own contract, institution, clinician, product documentation, local code, or governing standard may be the controlling source.
Guidance on unit names, symbols, conversions, and numerical presentation.
Questions about this calculation
How do I convert Centimetres to Kilometres?
result = input × 0.01 ÷ 1000. Input is in cm; result is in km. 1 cm = 0.00001 km. The displayed digits may be rounded.
What is 1 cm in km?
1 cm = 0.00001 km. The displayed digits may be rounded.
Can I reverse the cm to km conversion?
Yes. Swap the source and target units in the converter. The reverse relationship converts km back to cm.
Is the Centimetres to Kilometres result exact?
The conversion follows the displayed unit relationship. Display rounding can hide additional digits, and measured inputs cannot become more accurate merely by changing units.