Arpent to Parsec Conversion Calculator: Free Online Tool
Convert arpents to parsecs with our free online length converter.
Arpent to Parsec Calculator
How to Use the Calculator:
- Enter the value you want to convert in the 'From' field (Arpent).
- The converted value in Parsec 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 Arpent to Parsec
Converting Arpent to Parsec involves multiplying the value by a specific conversion factor, as shown in the formula below.
Formula:
1 Arpent = 1.8949e-15 parsecsExample Calculation:
Convert 10 arpents: 10 × 1.8949e-15 = 1.8949e-14 parsecs
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 Arpent and a Parsec?
The Arpent is a historical French unit used primarily for measuring land area, but also sometimes used as a unit of length. As a unit of length, the arpent typically referred to the side length of a square arpent of land.
Its precise length varied significantly by region and time period in France and its colonies. A commonly cited value, particularly associated with the arpent de Paris, is based on 180 French feet (pieds du Roi), which equates to approximately:
- 58.47 meters (m)
- 191.8 feet (ft)
Other variations existed, such as the arpent commun (based on 200 French feet, ~64.97 m) and the arpent d'ordonnance (based on 220 French feet, ~71.47 m).
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.
Note: The Arpent is part of the imperial/US customary system, primarily used in the US, UK, and Canada for everyday measurements. The Parsec belongs to the imperial/US customary system.
History of the Arpent and Parsec
The term "arpent" likely derives from the Gaulish arepennis, meaning "end of a field," suggesting its origins relate to agricultural land measurement, possibly representing the amount of land that could be plowed in a day. It became a fundamental unit for land surveying in France during the medieval period and remained in use until the adoption of the metric system following the French Revolution.
- Regional Variations: Before standardization efforts, the length (and thus area) of the arpent varied considerably across different regions of France. Key variations included:
- Arpent de Paris: Based on a perche (rod) of 18 pieds du Roi (French feet), with the linear arpent (side of the square) being 10 perches, totaling 180 pieds (~58.47 m). The area was 32,400 square pieds.
- Arpent Commun: Based on a perche of 20 pieds, linear arpent of 200 pieds (~64.97 m). Area: 40,000 square pieds.
- Arpent d'Ordonnance (or Arpent des Eaux et Forêts): Based on a perche of 22 pieds, linear arpent of 220 pieds (~71.47 m). Area: 48,400 square pieds. Used primarily for royal forests.
- Colonial Usage: The arpent was exported to French colonies, notably:
- New France (Quebec, Canada): The arpent de Paris became the standard for land grants along the St. Lawrence River, shaping the characteristic long, narrow farm plots (rangs).
- Louisiana (USA): The French arpent (usually the arpent de Paris) was used for land measurement before and sometimes after the Louisiana Purchase. Its legacy persists in land titles and some place names.
- Metrication: The metric system officially replaced the arpent and other traditional units in France in the late 18th and early 19th centuries, though its use lingered in practice and historical records.
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.
Common Uses for arpents and parsecs
Explore the typical applications for both Arpent (imperial/US) and Parsec (imperial/US) to understand their common contexts.
Common Uses for arpents
The Arpent (both linear and area) is now largely obsolete for practical measurement but remains historically significant:
- Historical Land Surveys: Essential for interpreting old maps, deeds, and land grants in France, Quebec, Louisiana, and other areas formerly under French control (e.g., parts of the US Midwest like Missouri, Illinois, Indiana).
- Legal Context: Land descriptions in some regions may still reference original measurements in arpents, requiring conversion for modern understanding.
- Historical Research: Understanding the arpent is crucial for historians studying agriculture, settlement patterns, and land tenure systems in French history and its colonial contexts.
- Unit of Area: While this page focuses on the length, the arpent is more commonly known and encountered as a unit of area (the square arpent).
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).
Frequently Asked Questions
Questions About Arpent (arpent)
Is the Arpent a unit of length or area?
The Arpent is primarily known as a unit of area, representing a specific parcel of land. However, a linear arpent also exists, defined as the side length of a square whose area is one arpent. This page focuses on the linear arpent. The relationship is direct: Area Arpent = (Linear Arpent)². Because the linear arpent varied, the area also varied.
Where is the Arpent still relevant?
The Arpent is not used for everyday measurements today. Its relevance is almost entirely historical and legal:
- Quebec (Canada): Crucial for understanding historical land division and property lines, especially the seigneurial system.
- Louisiana (USA): Important for interpreting land titles dating back to the French colonial period.
- France: Relevant for historical studies and understanding old documents.
- Other former French territories: May appear in historical records (e.g., Mauritius, parts of the US Midwest).
How long is a linear Arpent?
There is no single value, as it varied regionally. Common historical values include:
- Arpent de Paris: ~180 French feet ≈ 58.47 meters ≈ 191.8 feet (Most common in Quebec & Louisiana)
- Arpent Commun: ~200 French feet ≈ 64.97 meters ≈ 213.2 feet
- Arpent d'Ordonnance: ~220 French feet ≈ 71.47 meters ≈ 234.5 feet (Note: The French foot, pied du Roi, was slightly longer than the English foot, approx. 32.48 cm or 12.79 inches).
How does the linear Arpent compare to a Meter or Foot?
- The most common linear arpent (~58.47 m) is significantly longer than a meter. (1 Arpent ≈ 58.47 m)
- It is also much longer than a foot. (1 Arpent ≈ 191.8 ft)
Is the Arpent an SI unit?
No, the Arpent is not an SI unit. It is a traditional unit from the French system of measurements. The SI base unit for length is the meter (m), and the SI unit for area is the square meter (m²).
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.
Conversion Table: Arpent to Parsec
| Arpent (arpent) | Parsec (pc) |
|---|---|
| 1 | 0 |
| 5 | 0 |
| 10 | 0 |
| 25 | 0 |
| 50 | 0 |
| 100 | 0 |
| 500 | 0 |
| 1,000 | 0 |
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)
- 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)
- Ri (Japanese) (ri)
- Klafter (klafter)
- Yojana (yojana)
- Skein (skein)