This page describes an obsolete unit.

The unit described on this page was in use prior to modern methods of precision measurement. It was based on a standard which is no longer available, and which is not capable of being calibrated against modern measurement units. Therefore, the equivalence to modern SI units or to current United States customary units can only be considered approximate.

This system was in use in France prior to the Revolution. It was based on units promulgated by Charlemagne, but different areas had modified the values so that the same-named unit could have different values at different locations. The units listed in this wiki are the ones current in Paris in 1789, at the start of the Revolution.

The lengths given in the table below are more accurate than would be the case for other obsolete units, because the equivalence of 1 toise = 1.9490365 m was set by law when the metric system was adopted.

Name of unit Value in terms of smaller units Value in terms of the meter Value in terms of United States customary measure
point 0.0001879857735532407 0.0074010147068205 in.
ligne 12 points 0.0022558292826389 0.0888121764818461 in.
pouce 12 lignes 0.0270699513916667 1.065746117782154 in. = 0.0888121764818461 ft
pied 12 pouces 0.3248394166666667 1.065746117782154 ft = 0.35524870589093 yd
aune 2 pieds 0.6496788333333333 2.131492235564308 ft = 0.7104974118547693 yd
toise 3 aunes 1.9490365 2.131492235564308 yd = 0.001211075133719 mi
perche 3 toises 5.8471095 6.394476706036745 yd = 0.0036332254011572 mi
lieue 760 perches 4443.80322 2.761251305162854 mi