Lignes to Meters (ligne to m)

1 ligne equals 0.002255829062 meters (rounded).

1 ligne = 0.002255829062 meters

How to convert lignes to meters

To convert lignes to meters, multiply the number of lignes by 0.002255829062. The factor is rounded to 10 significant digits. To go the other way, multiply meters by 443.296.

meters = lignes × 0.002255829062

Example: 10 lignes = 0.02255829062 meters.

About these units

Ligne (ligne)

French (Ancien Régime)Historical unit (no longer in standard use)

One twelfth of a pouce (about 2.256 mm). The old French line; watchmakers still quote movement sizes in lignes.

Ligne is simply the French word for line, and the unit sat at the bottom of the Paris measuring ladder: twelve lignes made one pouce, and 144 made one pied du roi. Using the figure adopted in the 1799 metric law, in which one metre equals 443.296 lignes, a ligne comes to about 2.2558 millimetres.

Tailors, cabinetmakers and instrument makers of the Ancien Régime used it for fine dimensions that an inch was too coarse to express. A British line of one twelfth of an English inch also existed until 1824, so the two were similar in spirit but not identical, since the French inch was the longer one.

The unit outlived the monarchy in a few trades. French and Swiss watchmakers still describe the size of a movement or case in lignes, written with a triple prime mark, and milliners measure hat ribbon in it. The button trade uses a different ligne of one fortieth of an inch, about 0.635 millimetres, so the context always has to be checked.

1 ligne = 0.002255829062 meters (approximately).

Sources: Wikipedia: Ligne (unit); Wikipedia: Pied du roi; Wikipedia: Traditional French units of measurement

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

Related conversions

See all length units.