How many kilometres is 1 centimetre?

One centimetre equals exactly 0.00001 kilometres (1 cm = 0.00001 km). This is because there are 100 centimetres in a metre and 1,000 metres in a kilometre, giving 100,000 centimetres in a kilometre. To convert any value from cm to km, divide it by 100,000.

How do I convert centimetres to kilometres?

To convert centimetres to kilometres, divide the number of centimetres by 100,000. For example, 500,000 cm divided by 100,000 equals 5 km. You can also first convert cm to metres by dividing by 100, then convert metres to kilometres by dividing by 1,000, which gives the same result.

How many centimetres are in a kilometre?

There are exactly 100,000 centimetres in one kilometre. This comes from the metric system: 1 km = 1,000 m, and 1 m = 100 cm, so 1 km = 1,000 x 100 = 100,000 cm. To convert kilometres to centimetres, multiply by 100,000.

CM to KM Conversion Calculator

This calculator converts centimetres to kilometres using the exact metric relationship of 100,000 centimetres to one kilometre. Enter any value in centimetres and the tool instantly returns the equivalent in kilometres, along with the same length expressed in metres and millimetres, so you can see how the measurement scales across common units. You can also work backwards by entering a kilometre figure directly, and the centimetre field updates to match. A dropdown of common presets, including a marathon distance of 4,219,500 cm, lets you load typical figures without typing them out, and the results grid highlights the kilometre conversion alongside the centimetre, metre and millimetre equivalents. A worked example using the default 500,000 cm shows the formula in action: km = cm divided by 100,000, giving 5 km, 5,000 m and 5,000,000 mm. A reference table further down lists conversions for common centimetre values, from 1 cm through to marathon distance, so you can check figures quickly without recalculating. This conversion is most useful for map scales, athletics distances, scale models and any situation where small measurements in centimetres need to be understood in terms of real-world kilometre distances. Because the metric system is based on exact powers of ten, every result is precise, with no rounding needed for whole-number inputs.

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Standard metric conversion SI base units. 1 km = 1,000 m = 100,000 cm. Exact by definition.

Enter Value to Convert

Centimetres (cm)

Common values (click to load)

Result

Kilometres (km)

Also expressed as

Conversion Result

Centimetres

500,000

cm (input)

Kilometres
5
km (result)

Metres

5,000

Millimetres

5,000,000

Worked example (default values) Input: 500,000 cm
Formula: km = 500,000 / 100,000 = 5 km
Also: 500,000 cm = 5,000 m = 5,000,000 mm

Reference Conversion Table

Centimetres (cm)	Kilometres (km)	Metres (m)	Millimetres (mm)
1 cm	0.00001 km	0.01 m	10 mm
100 cm	0.001 km	1 m	1,000 mm
1,000 cm	0.01 km	10 m	10,000 mm
10,000 cm	0.1 km	100 m	100,000 mm
100,000 cm	1 km	1,000 m	1,000,000 mm
500,000 cm	5 km	5,000 m	5,000,000 mm
1,000,000 cm	10 km	10,000 m	10,000,000 mm
4,219,500 cm	42.195 km	42,195 m	42,195,000 mm

How to Convert Centimetres to Kilometres

The metric system is built on powers of 10, making conversions between units straightforward. To convert centimetres (cm) to kilometres (km), you divide by 100,000:

km = cm / 100,000

This factor comes directly from the metric prefix definitions. The prefix "centi" means one hundredth (1/100), so 1 cm = 0.01 m. The prefix "kilo" means one thousand, so 1 km = 1,000 m. Combining these: 1 km = 1,000 m x 100 cm/m = 100,000 cm.

Metric Length Units

Unit	Symbol	Relation to 1 metre	Relation to 1 km
Kilometre	km	1,000 m	1 km
Metre	m	1 m	0.001 km
Centimetre	cm	0.01 m	0.00001 km
Millimetre	mm	0.001 m	0.000001 km

When Would You Convert CM to KM?

Converting centimetres to kilometres is most common in:

Map reading: Map scales are often expressed in centimetres per kilometre. A 1:100,000 scale map means 1 cm on the map represents 1 km on the ground (100,000 cm).
Science and engineering: Small measurements (in cm) may need to be expressed in km for geospatial or transport calculations.
Athletics and sport: Track lengths measured in cm for precision can be reported in km for race distances.
Scale models: Model dimensions in cm may need to be compared to real-world distances in km.

Step-by-Step Conversion Method

Start with your value in centimetres.
Divide by 100 to convert to metres (cm / 100 = m).
Divide by 1,000 to convert metres to kilometres (m / 1,000 = km).
Or combine both steps: divide the original cm value by 100,000 to get km directly.

Example: Convert 750,000 cm to km. Dividing by 100,000: 750,000 / 100,000 = 7.5 km.

Related Calculators

Essential Calculators: full range of unit converters and everyday tools.
CM to M Converter: convert centimetres to metres.
CM to MM Converter: convert centimetres to millimetres.
Kilometre to Metre Converter: convert km to metres.
Metres to Feet Converter: metric to imperial length conversion.

Method: Standard SI metric conversion. 1 km = 1,000 m; 1 m = 100 cm; therefore 1 km = 100,000 cm exactly. International Bureau of Weights and Measures (BIPM), SI Brochure, 9th edition.

This conversion is exact within the SI metric system. No rounding is required for whole numbers of centimetres; decimal results are displayed to sufficient precision for practical use.