How to Convert Micrometres to Kilometres (µm to km)
Length conversions come up when reading overseas furniture specs, cycling the Round Island Route in kilometres while a foreign app shows miles, or checking marine distances in the Singapore Strait in nautical miles. This guide shows how to convert micrometres into kilometres by hand, with examples and a quick-reference table.
The conversion
To convert micrometres to kilometres, multiply the value by 1.000000e-09. To go the other way, divide by the same number (or multiply by 1.000000e+09). Because the factor is tiny, scientific notation keeps the numbers manageable.
Kilometres = micrometres × 1.000000e-09
Worked examples
- 3 µm = 3.000000e-9 km
- 12.5 µm = 1.250000e-8 km
- 75 µm = 7.500000e-8 km
Micrometres to Kilometres table
| Micrometres | Kilometres |
|---|---|
| 1 µm | 1.000000e-9 km |
| 2 µm | 2.000000e-9 km |
| 5 µm | 5.000000e-9 km |
| 10 µm | 1.000000e-8 km |
| 20 µm | 2.000000e-8 km |
| 25 µm | 2.500000e-8 km |
| 50 µm | 5.000000e-8 km |
| 100 µm | 1.000000e-7 km |
| 250 µm | 2.500000e-7 km |
| 500 µm | 5.000000e-7 km |
| 1,000 µm | 1.000000e-6 km |
Common questions
Is µm to km exact?
The factors used here are the internationally defined values where they exist; results are rounded for display only.
How do I convert back?
Use the Kilometres to Micrometres converter.
Mistakes to avoid
Multiplying when you should divide
Converting to a smaller unit gives a bigger number, and converting to a larger unit gives a smaller one. If your answer moves the wrong way, you have inverted the factor.
Rounding the factor too early
Using 3 instead of 3.28 for feet per metre introduces an error of almost 9% before you have started.
Dropping the units
A bare number without a unit is easy to misread later. Always write the unit with the result.
Background
A conversion table is handy for common values, but a calculator is faster and avoids interpolation errors for anything in between.
Unit conversion is simply multiplication by a fixed ratio. The ratio between two units of the same quantity never changes, so once you know it you can convert any value in either direction.
Singapore adopted the metric system in the 1970s, replacing imperial units and traditional Chinese measures in most official uses. Metric units are now standard in schools, trade and government, but older units survive in property, markets and imported goods.
For any value, use the Micrometres to Kilometres Converter or browse all length converters.
Run your own numbers: Micrometres to Kilometres Converter