Parsec to Digit Conversion Calculator: Free Online Tool
Convert parsecs to digits with our free online length converter.
Parsec to Digit Calculator
How to Use the Calculator:
- Enter the value you want to convert in the 'From' field (Parsec).
- The converted value in Digit 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 Digit
Converting Parsec to Digit involves multiplying the value by a specific conversion factor, as shown in the formula below.
Formula:
1 Parsec = 1.6198e+18 digitsExample Calculation:
Convert 10 parsecs: 10 × 1.6198e+18 = 1.6198e+19 digits
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.
Not for professional use. Results should be verified before use in any critical application. View our Terms of Service for more information.
What is a Parsec and a Digit?
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 Digit, also known as the finger or fingerbreadth, is an ancient, anthropomorphic unit of length, originally based on the breadth (width) of a human adult finger (typically the index finger). As a body-based unit, its value varied significantly depending on the person, time period, and culture.
Historically, it was often considered to be approximately 3/4 of an inch or about 1.9 centimeters (cm). In many systems, it formed a subdivision of larger units like the palm, span, or cubit. For example, it was common for:
- 4 digits = 1 palm
- 12 digits = 1 span (sometimes)
- 24 or 28 digits = 1 cubit (depending on the cubit definition)
Note: The Parsec is part of the imperial/US customary system, primarily used in the US, UK, and Canada for everyday measurements. The Digit belongs to the imperial/US customary system.
History of the Parsec and Digit
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.
The digit is one of the oldest known units of measurement, used by ancient civilizations including the Egyptians, Mesopotamians, Greeks, Romans, and later across Europe. Its convenience stemmed from the ready availability of the human hand for estimation.
- Ancient Egypt: The digit (djeba) was a fundamental unit, with 28 digits forming the Royal Cubit.
- Ancient Rome: The Roman digit (digitus) was defined as 1/16 of a Roman foot, approximately 1.85 cm. Four digiti made a palmus (palm).
- Medieval England: The digit was often reckoned as 3/4 of an inch, derived from the barleycorn (3 barleycorns = 1 inch, 4 digits = 3 inches).
Due to its inherent variability and the rise of more standardized systems based on physical prototypes (like the yard or meter), the digit gradually fell out of practical use for trade and science, becoming largely obsolete by the early modern period.
Common Uses for parsecs and digits
Explore the typical applications for both Parsec (imperial/US) and Digit (imperial/US) 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 digits
The digit is now obsolete for practical measurement but is encountered in:
- Historical Texts: Found in ancient and medieval documents describing dimensions of objects, buildings, or anatomical measurements.
- Archaeology & Anthropology: Used when interpreting historical measurements or comparing ancient systems.
- Figurative Language: Occasionally used informally to mean a very small distance ("just a digit more").
- Understanding Historical Units: Key to understanding the structure of ancient measurement systems (e.g., relationship to palm, cubit).
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 Digit (digit)
How long is a digit?
There is no single, precise value for the digit because it was based on human anatomy and varied by system. Common historical approximations include:
- Approximately 0.75 inches (in)
- Approximately 1.85 to 1.9 centimeters (cm)
- Often defined as 1/4 of a palm or 1/16 of a foot within specific historical systems.
What is the relation between a digit and a palm?
In many historical systems (like the Roman and often the English), 4 digits were considered equal to 1 palm (the width of the hand across the base of the fingers).
What is the relation between a digit and a cubit?
The relationship varied. For example:
- The Egyptian Royal Cubit contained 28 digits.
- The common Greek and Roman cubits often contained 24 digits.
Is the digit an SI unit?
No, the digit is not an SI unit. It is an ancient, non-standardized, anthropomorphic unit. The corresponding SI unit for length is the meter (m).
Is the digit still used today?
No, the digit is not used for any standard or practical measurements today. Its use is confined to historical study, interpretation of old texts, and occasional figurative speech.
Where does the name 'digit' come from?
The name comes from the Latin word digitus, which means "finger" or "toe". This reflects the unit's origin based on the width of a human finger.
Conversion Table: Parsec to Digit
| Parsec (pc) | Digit (digit) |
|---|---|
| 1 | 1,619,790,026,246,719,000 |
| 5 | 8,098,950,131,233,595,000 |
| 10 | 16,197,900,262,467,190,000 |
| 25 | 40,494,750,656,167,980,000 |
| 50 | 80,989,501,312,335,950,000 |
| 100 | 161,979,002,624,671,900,000 |
| 500 | 809,895,013,123,359,500,000 |
| 1,000 | 1,619,790,026,246,719,000,000 |
All Length Conversions
Other Units from Length
- Meter (m)
- Kilometer (km)
- 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)
- 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)