Parsec to Kilometer Conversion Calculator: Free Online Tool
Convert parsecs to kilometers with our free online length converter.
Parsec to Kilometer Calculator
How to Use the Calculator:
- Enter the value you want to convert in the 'From' field (Parsec).
- The converted value in Kilometer will appear automatically in the 'To' field.
- Use the dropdown menus to select different units within the Length category.
- Click the swap button (⇌) to reverse the conversion direction.
How to Convert Parsec to Kilometer
Converting Parsec to Kilometer involves multiplying the value by a specific conversion factor, as shown in the formula below.
Formula:
1 Parsec = 3.0857e+13 kilometersExample Calculation:
Convert 10 parsecs: 10 × 3.0857e+13 = 3.0857e+14 kilometers
Disclaimer: For Reference Only
These conversion results are provided for informational purposes only. While we strive for accuracy, we make no guarantees regarding the precision of these results, especially for conversions involving extremely large or small numbers which may be subject to the inherent limitations of standard computer floating-point arithmetic.
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What is a Parsec and a Kilometer?
The Parsec (symbol pc) is a unit of length used to measure the enormous distances to astronomical objects outside the Solar System. One parsec is defined as the distance at which one astronomical unit (AU) – the average distance between the Earth and the Sun – subtends an angle of one arcsecond (1/3600th of a degree). This corresponds to approximately:
- 3.0857 × 10¹⁶ meters (m)
- 30.857 trillion kilometers (km)
- 19.174 trillion miles (mi)
- 206,264.8 astronomical units (AU)
- 3.26156 light-years (ly)
It is derived directly from the method of trigonometric parallax used by astronomers to measure stellar distances.
The kilometer is a unit of length in the metric system equal to one thousand meters (1,000 m). It is commonly used to measure geographic distances.
Note: The Parsec is part of the imperial/US customary system, primarily used in the US, UK, and Canada for everyday measurements. The Kilometer belongs to the metric (SI) system.
History of the Parsec and Kilometer
The concept of measuring stellar distances via parallax existed long before the unit itself. The term "parsec" was coined by the British astronomer Herbert Hall Turner in 1913. He sought a convenient unit for astronomers that directly reflected the observational method. The name is a portmanteau derived from "parallax of one arcsecond". It quickly gained acceptance within the astronomical community due to its practical connection to parallax measurements, which were (and still are) a fundamental way to determine distances to nearby stars.
Derived directly from the meter, the kilometer was established as part of the metric system in the late 18th century to provide a larger, convenient unit for measuring longer distances, such as those between cities or the lengths of roads.
Common Uses for parsecs and kilometers
Explore the typical applications for both Parsec (imperial/US) and Kilometer (metric) to understand their common contexts.
Common Uses for parsecs
The parsec is the preferred unit of distance in professional astronomy and astrophysics:
- Stellar Distances: Measuring distances to nearby stars using parallax.
- Galactic Structure: Describing distances within the Milky Way galaxy (often using kiloparsecs, kpc, where 1 kpc = 1000 pc). For example, the Sun is about 8 kpc from the Galactic Center.
- Extragalactic Distances: Measuring distances to other galaxies and galaxy clusters (often using megaparsecs, Mpc, where 1 Mpc = 1,000,000 pc). The Hubble constant, describing the expansion of the universe, is typically expressed in (km/s)/Mpc.
- Cosmology: Discussing large-scale structures and distances in the universe (using Mpc and sometimes gigaparsecs, Gpc, where 1 Gpc = 1000 Mpc).
Common Uses for kilometers
- Geography & Travel: Measuring distances between geographical locations (cities, countries).
- Transportation: Road signs indicating distances and speed limits (km/h) in metric countries.
- Mapping: Measuring the length of roads, rivers, or coastlines.
- Athletics: Athletic events like long-distance running (e.g., 5k, 10k, marathon).
- Logistics: Calculating travel times and fuel efficiency.
Frequently Asked Questions
Questions About Parsec (pc)
What does 'Parsec' stand for?
Parsec is a blend of "parallax of one arcsecond". It represents the distance at which the parallax angle of a star is exactly one second of arc.
How is a parsec defined?
It's defined based on trigonometry. Imagine a right-angled triangle in space where the short side is the Earth-Sun distance (1 AU). The parsec is the length of the adjacent side when the angle at the distant star (the parallax angle) is exactly one arcsecond.
Is a Parsec bigger than a Light Year?
Yes, one parsec is significantly larger than one light-year.
- 1 Parsec ≈ 3.26 light-years
How many meters or kilometers are in a parsec?
One parsec is approximately:
- 3.0857 × 10¹⁶ meters
- 30.857 trillion kilometers
How many Astronomical Units (AU) are in a parsec?
One parsec is equal to approximately 206,265 AU. This number arises directly from the definition involving radians and arcseconds (specifically, the number of arcseconds in a radian).
Why do astronomers use parsecs instead of light-years?
While both are used, parsecs are often preferred in professional contexts because:
- Direct Observational Link: The parsec is derived directly from the parallax angle, a primary method for measuring distance.
- Historical Convention: It became the standard unit early in the development of stellar distance measurement.
- Convenience: Multiples like kpc and Mpc provide convenient scales for galactic and extragalactic distances.
- Definition Stability: The definition of a light-year depends slightly on the definition of a "year" (e.g., Julian year), whereas the parsec is based on the fixed AU and geometric angles.
Is the parsec an SI unit?
No, the parsec is not an SI unit. The SI unit for length is the meter (m). However, the parsec (along with the astronomical unit and light-year) is recognized by the International Astronomical Union (IAU) and is widely accepted for use in astronomy.
About Kilometer (km)
How many meters are in a kilometer?
There are exactly 1,000 meters (m) in 1 kilometer (km).
What does 'kilo' mean in kilometer?
The prefix 'kilo' denotes one thousand (1,000).
Is a kilometer longer or shorter than a mile?
A kilometer is shorter than a mile. One mile is approximately 1.609 kilometers.
Conversion Table: Parsec to Kilometer
| Parsec (pc) | Kilometer (km) |
|---|---|
| 1 | 30,857,000,000,000 |
| 5 | 154,285,000,000,000 |
| 10 | 308,570,000,000,000 |
| 25 | 771,425,000,000,000 |
| 50 | 1,542,850,000,000,000 |
| 100 | 3,085,700,000,000,000 |
| 500 | 15,428,500,000,000,000 |
| 1,000 | 30,857,000,000,000,000 |
All Length Conversions
Other Units from Length
- Meter (m)
- Hectometer (hm)
- Decimeter (dm)
- Centimeter (cm)
- Millimeter (mm)
- Inch (in)
- Foot (ft)
- Yard (yd)
- Mile (mi)
- Nautical Mile (NM)
- Micrometer (μm)
- Nanometer (nm)
- Light Year (ly)
- Astronomical Unit (AU)
- Angstrom (Å)
- Point (Typography) (pt)
- Mil/Thou (mil)
- Fathom (fath)
- Furlong (fur)
- Link (Gunter's) (li)
- Pace (pace)
- Span (span)
- Digit (digit)
- Cable Length (cb)
- Ell (ell)
- Finger (finger)
- Roman Mile (m.p.)
- Stadion (stadion)
- Chi (Chinese) (chi)
- Shaku (Japanese) (shaku)
- Li (Chinese) (li)
- Toise (toise)
- Bolt (bolt)
- Rope (rope)
- Smoot (smoot)
- Sajene (sajene)
- Ken (ken)
- Wa (wa)
- Vara (vara)
- Aln (aln)
- Cubit (Royal/Egyptian) (cubit)
- Versta (versta)
- Arpent (arpent)
- Ri (Japanese) (ri)
- Klafter (klafter)
- Yojana (yojana)
- Skein (skein)