Square Rods to Acres (sq rd to ac)

1 square rod equals 0.00625 acres exactly.

1 square rod = 0.00625 acres

How to convert square rods to acres

To convert square rods to acres, multiply the number of square rods by 0.00625. This factor is exact. To go the other way, multiply acres by 160.

acres = square rods × 0.00625

Example: 10 square rods = 0.0625 acres.

About these units

Square Rod (sq rd)

US & ImperialTraditional unit (still used in some regions)

30.25 square yards (25.29 m²), also called a perch. 160 square rods make an acre.

Perch is the older name for this small square, and it traces back to the Roman pertica, a measuring pole. The word rod became the preferred surveyors' term in England, where land measurers carrying rods, poles or knotted cords were in demand after Henry VIII took over church estates in 1536. A square rod is the square on a rod of 16.5 feet, which works out to 272.25 square feet, or 30.25 square yards.

The odd-looking number makes sense through the acre. Edmund Gunter's 66-foot chain is four rods long, so a square chain holds 16 square rods, and ten square chains make an acre. That means 160 square rods fill an acre, and a rood holds 40. Metric equivalents are about 25.29 square meters, a little under the floor area of a small garage. Rods and perches turned up in deeds, tax records and plot descriptions for centuries, and a few English-speaking regions still quote small building plots in perches.

1 square rod = 25.29285264 square meters (exactly).

Sources: Wikipedia: Rod (unit); Wikipedia: Chain (unit); Wikipedia: Acre

Acre (ac)

US & ImperialCurrent unit

43,560 square feet or exactly 4,046.8564224 m², about 40% of a hectare. Originally the area a yoke of oxen could plow in a day.

Ploughland gave the acre its name: it traces to Old Norse akr, meaning cultivated land, and is related to German Acker and Latin ager. In medieval England it was a farming measure, the land one man with a team of eight oxen could plough in a day. The traditional strip was 40 perches long and 4 perches wide, which is 660 by 66 feet, or ten square chains. The shape was never the point, and the article on the unit stresses that any area of 43,560 square feet is an acre.

An acre is 43,560 square feet, 4,840 square yards or 1/640 of a square mile, close to 0.4 hectare. For Americans, it is roughly 88 by 55 yards, about 90 percent of a football field without the end zones. The Weights and Measures Act 1878 fixed it at 4,840 square yards in Britain, where trade use ended in 1995. The 1959 international acre is exactly 4,046.8564224 m²; the US survey acre, about 4,046.872 m², differed slightly, and US survey units were retired after 2022.

1 acre = 4,046.856422 square meters (approximately).

Sources: Wikipedia: Acre; NIST Guide to the SI, Appendix B.8: conversion factors

Related conversions

See all area units.