Convert Centimeter to Kilometer
Convert centimeters to kilometers instantly. 1 centimeter = 1e-5 kilometer — use the live calculator, the exact formula, a conversion table and worked examples. Also check the Kilometer to Centimeter converter for the reverse conversion.
Units explained
Centimeter
A centimeter is a metric unit of length equal to one hundredth of a meter (1/100 m). It is one of the most commonly used SI sub-units in daily life, especially for measuring small objects, body dimensions, paper sizes, and short distances.
The centimeter emerged from the French metric system established by the French Academy of Sciences in 1793. The metric system introduced decimal-based prefixes (milli-, centi-, deci-, deca-, hecto-, kilo-) to create proportional sub-units of the meter.
Centimeters are the standard unit for everyday measurement in nearly every country outside the United States. They are used for body height, clothing sizes, rainfall, paper formats (A4 is 21 × 29.7 cm), screen dimensions, and most consumer product specifications.
Developed in France during the late 18th century as part of the metric system designed by the French Academy of Sciences. Formally adopted in France in 1795 and ratified internationally through the Metre Convention signed in Paris in 1875.
Kilometer
A kilometer is a metric unit of length equal to one thousand meters. It is the standard unit for measuring road distances, geographic distances, and other large-scale measurements in metric countries.
The kilometer was defined alongside the meter in 1795 using the standard SI prefix kilo- (from Greek chilioi, "thousand"), denoting one thousand units.
Kilometers are used worldwide (except the United States and a few others) for road signage, geographic distance, athletic events, and scientific distances at planetary scale. Speed limits in most countries are given in km/h.
Adopted 1795 in France as part of the original metric system; the kilometer became the global standard for road and geographic distance through the 19th and 20th century metric adoption.
Centimeter to Kilometer conversion formula
The relationship between centimeters and kilometers:
To convert centimeters to kilometers, multiply the value in centimeters by 1e-5. To reverse, multiply kilometers by 100000.
How to use this converter
Type a value into the calculator. The result in kilometers updates as you type. Tap a quick value, copy the result with one click, or use the swap arrow to jump straight to the Kilometer to Centimeter converter for the reverse direction.
Step-by-step: convert centimeters to kilometers
- Write down the value in centimeters (cm).
- Multiply that value by the factor 1e-5.
- The product is the equivalent value in kilometers (km).
- To reverse, multiply the kilometer value by 100000.
Worked examples
Example 1 — Convert 1 cm to km:
1 × 1e-5 = 1e-5 km
Example 2 — Convert 100 cm to km:
100 × 1e-5 = 0.001 km
Real-world example — Astronomical-class conversion
100,000 cm equals 1 km — the kind of conversion that comes up when small-scale survey diagrams must be related to road-network distances on a different map. The five-order-of-magnitude jump is the largest practical metric conversion.
100000 cm × 1e-5 = 1 km
Real-world example — Marathon distance in centimeters
500,000 cm equals 5 km. The conversion isn't routine, but it shows up in physics problems and engineering exercises where the same distance must be expressed at multiple scales for unit-analysis purposes.
500000 cm × 1e-5 = 5 km
Real-world example — One-meter standard scale
1,000,000 cm equals 10 km. The conversion is most useful as a sanity check in unit-analysis problems where verifying that a centimeter measurement scales reasonably to a kilometer one is part of catching computation errors.
1000000 cm × 1e-5 = 10 km
Centimeter to Kilometer conversion table
Standard reference values for converting centimeters to kilometers:
| Centimeter [cm] | Kilometer [km] |
|---|---|
| 0.01 | 1e-7 |
| 0.1 | 1e-6 |
| 1 | 1e-5 |
| 2 | 2e-5 |
| 3 | 3e-5 |
| 4 | 4e-5 |
| 5 | 5e-5 |
| 10 | 0.0001 |
| 20 | 0.0002 |
| 30 | 0.0003 |
| 40 | 0.0004 |
| 50 | 0.0005 |
| 100 | 0.001 |
| 500 | 0.005 |
| 1000 | 0.01 |
Frequently asked questions
How many kilometers is 1 centimeter?
How do I convert centimeters to kilometers?
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How many kilometers is 100 centimeters?
Popular length unit conversions
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Metric / SI (17 units)
Imperial / US Customary (27 units)
Nautical (1 units)
Astronomical (9 units)
Atomic / Physics (6 units)
Typographic (3 units)
Sources & references
Conversion factor (1 cm = 1e-5 km) verified against the following authoritative sources:
- BIPM — The International System of Units (SI Brochure 9th ed.)
Official BIPM publication defining the seven SI base units (including the meter) and the rules for their use. The global authority on units of measurement.
- NIST — Guide to the SI
US National Institute of Standards and Technology reference covering the SI base and derived units with definitions and usage rules for US technical practice.
- NIST Special Publication 811 — Guide for the Use of the International System of Units
Detailed NIST guide covering exact conversion factors between SI and US customary units along with formatting and rounding conventions.
- NIST — Refinement of values for the yard and pound (Federal Register 1959)
The treaty (signed by US
- International Hydrographic Organization — Resolution on the Nautical Mile
International authority that standardised the nautical mile at exactly 1852 m in 1929 — the value adopted worldwide for sea and air navigation.