Kilometers to Centimeters Converter
Convert kilometers to centimeters — multiply by 100,000. Results update as you type; exact factors shown.
One kilometer is 100,000 centimeters — see the exact factor, not a rounded rule of thumb.
How the kilometers to centimeters converter works
Every length is converted through the meter, 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 US uses customary units (US gallon, short ton, °F) in daily life; NIST SP 811 gives the exact SI factors.
Common length conversions
| From | To | Units |
|---|---|---|
| 0.001 km | 100 cm | kilometers to centimeters |
| 0.01 km | 1,000 cm | kilometers to centimeters |
| 0.1 km | 10,000 cm | kilometers to centimeters |
| 0.5 km | 50,000 cm | kilometers to centimeters |
| 1 km | 100,000 cm | kilometer to centimeters |
| 2 km | 200,000 cm | kilometers to centimeters |
| 5 km | 500,000 cm | kilometers to centimeters |
| 10 km | 1,000,000 cm | kilometers to centimeters |
| 21.0975 km | 2,109,750 cm | kilometers to centimeters |
| 42.195 km | 4,219,500 cm | kilometers to centimeters |
| 100 km | 10,000,000 cm | kilometers to centimeters |
| 1,000 km | 100,000,000 cm | kilometers to centimeters |
Units in this converter and their exact factors
| Unit | Symbol | One unit in meters |
|---|---|---|
| millimeter | mm | 0.001 meter |
| centimeter | cm | 0.01 meter |
| meter | m | 1 meter |
| kilometer | km | 1,000 meter |
| inch | in | 0.0254 meter |
| foot | ft | 0.3048 meter |
| yard | yd | 0.9144 meter |
| mile | mi | 1,609.344 meter |
| nautical mile | nmi | 1,852 meter |
FAQFrequently asked questions about length conversion
How many centimeters in a kilometer?
Exactly 100,000 — a hundred to the meter and a thousand meters to the kilometer.
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 centimeters?
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 Institute of Standards and Technology (NIST) — United States's national measurement authority.
Last checked: September 2026. Conversion factors are fixed by definition and do not change with tax years or regulations.