Meters to Parsecs (m to pc)

1 meter equals 3.240779289×10⁻¹⁷ parsecs (rounded).

1 meter = 3.240779289×10⁻¹⁷ parsecs

How to convert meters to parsecs

To convert meters to parsecs, multiply the number of meters by 3.240779289×10⁻¹⁷. The factor is rounded to 10 significant digits. To go the other way, multiply parsecs by 3.085677581×10¹⁶ (rounded).

parsecs = meters × 3.240779289×10⁻¹⁷

Example: 10 meters = 3.240779289×10⁻¹⁶ parsecs.

About these units

Meter (m)

Metric (SI)Current unit

The SI base unit of length. Since 1983 it is defined as the distance light travels in a vacuum in 1/299,792,458 of a second.

Meter comes from the Greek metron, a measure. In 1791 the French National Assembly defined it as one ten-millionth of the distance from the equator to the North Pole along a great circle through Paris, after rejecting the length of a seconds pendulum because that length changes with local gravity. The surveyors Delambre and Méchain measured the meridian arc, and in 1799 a platinum bar known as the Mètre des Archives became the physical standard. NIST notes that this Earth-based meter turned out to be about 0.2 mm shorter than the true pole-to-equator fraction it was meant to represent.

The 1875 Treaty of the Meter created the CGPM and the BIPM to look after common standards, and in 1889 a platinum-iridium prototype bar took over; the original is still kept at the BIPM. In 1960 the meter was tied to 1,650,763.73 wavelengths of an orange-red krypton-86 line, and in 1983 to the speed of light, which made length a quantity derived from the time standard. The 2018 revision reworded that definition without changing the meter's size. NIST offers a handy yardstick for scale: a pace, meaning two steps, is roughly a meter or a yard.

The meter is the reference unit for length on this site.

Sources: BIPM: history of the metre; NIST: the meter and the SI redefinition; Wikipedia: Metre

Parsec (pc)

AstronomicalCurrent unit

About 3.26 light-years, defined as 648,000/π astronomical units. The standard unit for distances to stars.

British astronomer Herbert Hall Turner coined the word in 1913 as a contraction of the distance at which a parallax equals one arcsecond. Rivals were Frank Dyson's astron and Carl Charlier's siriometer. The idea rests on stellar parallax, first measured successfully by Friedrich Bessel in 1838 for 61 Cygni, which he put near 3.5 parsecs. With the angle in arcseconds, the distance in parsecs is simply its reciprocal.

Since 2015 the IAU has defined the parsec as exactly 648,000 divided by pi astronomical units, which with the 2012 exact au gives about 30,856,775,814,913,673 meters, or 3.0857 times ten to the sixteenth power. That is roughly 3.26 light-years. Proxima Centauri lies about 1.3 parsecs away. Professional astronomers still prefer the parsec to the light-year, and ESA's Gaia satellite, launched in 2013, measures parallaxes to microarcsecond precision.

1 parsec = 3.085677581×10¹⁶ meters (approximately).

Sources: Wikipedia: Parsec; NIST SP 811 Appendix B.8: factors for units outside the SI

Related conversions

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