Nanometers to Kilometers
An instant nanometers-to-kilometers converter, with the formula and a reference table below.
| Nanometers | Kilometers |
|---|---|
| 1 nm | 1e-12 km |
| 2 nm | 2e-12 km |
| 3 nm | 3e-12 km |
| 5 nm | 5e-12 km |
| 10 nm | 1e-11 km |
| 25 nm | 2.5e-11 km |
| 50 nm | 5e-11 km |
| 100 nm | 1e-10 km |
How to use
- Enter a value in the Nanometers field.
- The Kilometers figure appears immediately — no button to press.
- Typing in the Kilometers field converts back to Nanometers the same way.
- Use the reference table for the values that come up most often.
Nanometers to Kilometers formula
To convert nanometers to kilometers, multiply by 1e-12.
km = nm × 1e-12
Why this factor: the nanometer and the kilometer are both defined against the meter, so dividing one definition by the other gives 1e-12 directly. Both definitions are set out in full below.
To go the other way, divide by 1e-12 — or use the Kilometers to Nanometers converter, which is the same calculation reversed.
Worked example
Given 12 nm, multiplying by 1e-12 yields 1.2e-11 km.
12 nm × 1e-12 = 1.2e-11 km
The converter above does this for any value you type, in either direction.
What is a nanometer?
A nanometer is one billionth of a meter — the scale of molecules and visible light wavelengths.
Definition: Exactly 1×10⁻⁹ meter by SI prefix definition.
Where it is used: Semiconductor process nodes, optical coatings, and wavelengths (visible light is roughly 380–750 nm).
What is a kilometer?
A kilometer is 1,000 meters, the standard unit for road distances and geography in most of the world.
Definition: Exactly 1,000 meters by SI prefix definition — 'kilo' means 10³.
Where it is used: Road signs, running and cycling distances, and map scales outside the US and UK.
Nanometers vs Kilometers
The nanometer and the kilometer belong to the same family of units, so converting between them is usually a matter of shifting a decimal point or applying a small whole-number factor.
Frequently asked questions
How many kilometers are in a nanometer?
One nanometer equals 1e-12 kilometers.
What is the formula to convert nanometers to kilometers?
Multiply the number of nanometers by 1e-12. To reverse it, divide by 1e-12 instead.
How do I convert kilometers back to nanometers?
Divide by 1e-12, which is the same as multiplying by 1e+12.
How many kilometers are in 10 nanometers?
10 nm works out to 1e-11 km.
How is the nanometer defined?
Exactly 1×10⁻⁹ meter by SI prefix definition.