Kilometres to Centimetres Converter
Convert kilometres to centimetres — multiply by 100,000. Results update as you type; exact factors shown.
One kilometre is 100,000 centimetres — see the exact factor, not a rounded rule of thumb.
How the kilometres to centimetres converter works
Every length is converted through the metre, the SI base unit of length. The inch has been defined as exactly 25.4 mm since the 1959 international yard and pound agreement, so a foot is exactly 0.3048 m, a yard 0.9144 m and a statute mile 1,609.344 m. The nautical mile is 1,852 m by international definition.
The UK is metric for most trade and science but keeps miles, pints, stone and mpg (with the imperial gallon) in daily life.
Common length conversions
| From | To | Units |
|---|---|---|
| 0.001 km | 100 cm | kilometres to centimetres |
| 0.01 km | 1,000 cm | kilometres to centimetres |
| 0.1 km | 10,000 cm | kilometres to centimetres |
| 0.5 km | 50,000 cm | kilometres to centimetres |
| 1 km | 100,000 cm | kilometre to centimetres |
| 2 km | 200,000 cm | kilometres to centimetres |
| 5 km | 500,000 cm | kilometres to centimetres |
| 10 km | 1,000,000 cm | kilometres to centimetres |
| 21.0975 km | 2,109,750 cm | kilometres to centimetres |
| 42.195 km | 4,219,500 cm | kilometres to centimetres |
| 100 km | 10,000,000 cm | kilometres to centimetres |
| 1,000 km | 100,000,000 cm | kilometres to centimetres |
Units in this converter and their exact factors
| Unit | Symbol | One unit in metres |
|---|---|---|
| millimetre | mm | 0.001 metre |
| centimetre | cm | 0.01 metre |
| metre | m | 1 metre |
| kilometre | km | 1,000 metre |
| inch | in | 0.0254 metre |
| foot | ft | 0.3048 metre |
| yard | yd | 0.9144 metre |
| mile | mi | 1,609.344 metre |
| nautical mile | nmi | 1,852 metre |
FAQFrequently asked questions about length conversion
How many centimetres in a kilometre?
Exactly 100,000 — a hundred to the metre and a thousand metres to the kilometre.
What is 1 km in cm?
100,000 cm.
How do I convert km to cm?
Move the decimal point five places right.
When would I need this?
Map scaling, and physics problems that mix scales. Everyday distances rarely span both.
What is a marathon in centimetres?
4,219,500 cm — 42.195 km.
Where these figures come from
- BIPM — The International System of Units (SI Brochure, 9th edition) — definitions of the base and derived units.
- NIST Special Publication 811 — Guide for the Use of the International System of Units — the exact conversion factors used here.
- National Physical Laboratory (NPL) — United Kingdom's national measurement authority.
Last checked: September 2026. Conversion factors are fixed by definition and do not change with tax years or regulations.