Kilometer is 1000 meter units.
Kilometers to Parsecs Converter — km to pc
Convert Kilometer (km) to Parsec (pc) using the exact conversion factor (1 kilometer = 3.240779e-14 parsec). See the formula, worked examples, conversion table, unit comparison, history, and common uses.
Kilometers to Parsecs converter
Converter
Length Converter
Convert SI, imperial, US customary, astronomical, scientific, and historical length units.
Context values
Some unit families need one extra value for a physically accurate result.
A parsec is about 3.26156 light-years.
Result = input x 1000 / 3.08567758e+16.
Length uses the meter as the base unit.
Reserved above the conversion cards and below the converter.
About Converting Kilometers to Parsecs
Kilometer and Parsec both measure length. Kilometer is typically associated with standard road, distance, and mapping unit in nearly every country except the United States, while Parsec is typically associated with standard distance unit throughout professional astronomy worldwide.
Formula
parsecs = kilometers × 3.240779e-14
This factor comes from each unit's defined relationship to the category's base unit: 1 kilometer equals 1000 base units, and 1 parsec equals 3.085678e+16 base units, so dividing one by the other gives the direct kilometer-to-parsec factor of 3.240779e-14.
Simple example
1 km × 3.240779e-14 = 3.240779e-14 pc
1 kilometer = 3.240779e-14 parsecs.
Real-world example
10 km × 3.240779e-14 = 3.240779e-13 pc
10 kilometers = 3.240779e-13 parsecs.
Conversion table
| Kilometer (km) | Parsec (pc) |
|---|---|
| 1 km | 3.240779e-14 pc |
| 5 km | 1.62039e-13 pc |
| 10 km | 3.240779e-13 pc |
| 21.0975 km | 6.837234e-13 pc |
| 42.195 km | 1.367447e-12 pc |
| 100 km | 3.240779e-12 pc |
Reverse conversion: Parsec to Kilometer
3.240779e-14 pc × 3.085678e+13 = 0.9999999107 km
3.240779e-14 parsecs = 0.9999999107 kilometers.
kilometers = parsecs × 3.085678e+13
For a page dedicated to this direction, see Parsec to Kilometer.
Kilometer vs. Parsec
| Aspect | Kilometer | Parsec |
|---|---|---|
| Family | SI derived (metric prefix) unit | non-SI unit used in astronomy |
| Typical use | Road signage, speed limits, and vehicle odometers outside the US | Measuring distances to nearby stars via parallax |
| Where it's used | Standard road, distance, and mapping unit in nearly every country except the United States | Standard distance unit throughout professional astronomy worldwide |
Understanding the Kilometer
Kilometer (km) measures distance. A kilometer is 1,000 meters — the meter is the SI base unit of length. It is classified as a SI derived (metric prefix) unit.
Where it's used: Standard road, distance, and mapping unit in nearly every country except the United States
Uses of the Kilometer today
- Road signage, speed limits, and vehicle odometers outside the US
- Geographic and mapping distances
- Endurance sports (marathons are measured in kilometers internationally, though the marathon distance itself is a fixed value in both systems)
History of the Kilometer
The meter was defined during the French Revolutionary metric reforms as one ten-millionth of the distance from the North Pole to the Equator along a meridian through Paris. 'Kilo-' is simply the SI prefix for 1,000, making the kilometer a direct decimal multiple.
The meter itself has been redefined several times as measurement precision improved — from a physical platinum-iridium bar (1889) to a krypton-86 wavelength (1960) to its current definition (1983) as the distance light travels in a fixed fraction of a second.
Historical origin. Kilometer was not the invention of a single named person; it developed through the process described above.
Understanding the Parsec
Parsec (pc) measures astronomical distance. The distance at which one astronomical unit subtends an angle of one arcsecond — approximately 3.26 light-years, or about 3.086 × 10¹⁶ meters. It is classified as a non-SI unit used in astronomy.
Where it's used: Standard distance unit throughout professional astronomy worldwide
Uses of the Parsec today
- Measuring distances to nearby stars via parallax
- Galactic and extragalactic distance scales in astrophysics research
History of the Parsec
The name is a portmanteau of 'parallax' and 'arcsecond,' reflecting how the unit is defined directly from the parallax method astronomers use to measure stellar distances: the tiny apparent shift in a nearby star's position as Earth orbits the Sun.
Historical origin. Parsec was not the invention of a single named person; it developed through the process described above.
Kilometer — sources
- BIPM — The metre (SI base unit) — Current definition and history of the meter.
Parsec — sources
- IAU (International Astronomical Union) — parsec definition — Standard astronomical definition of the parsec via stellar parallax.
Reserved between the cards and the FAQ so the page stays balanced.
Frequently asked questions
How many parsecs are in 1 kilometer?
1 kilometer equals 3.240779e-14 parsecs, using the exact defined conversion factor rather than an estimate.
How do I convert kilometer to parsec?
Multiply the kilometer value by 3.240779e-14. The converter above does this instantly to whatever precision you set.
How do I convert parsec back to kilometer?
Use the reverse factor: 1 parsec equals 3.085678e+13 kilometers. You can also use the swap control in the converter above to flip the direction instantly.
What is a kilometer?
Kilometer (km) measures distance. A kilometer is 1,000 meters — the meter is the SI base unit of length. It is classified as a SI derived (metric prefix) unit.
What is a parsec?
Parsec (pc) measures astronomical distance. The distance at which one astronomical unit subtends an angle of one arcsecond — approximately 3.26 light-years, or about 3.086 × 10¹⁶ meters. It is classified as a non-SI unit used in astronomy.
Is the kilometer to parsec conversion exact?
Yes. Both kilometer and parsec are defined by fixed standards rather than physical artifacts, so the factor of 3.240779e-14 used above is exact to as many digits as you choose to display.
Where is the kilometer still used today?
Standard road, distance, and mapping unit in nearly every country except the United States