Acres to Dunams (ac to dunam)

1 acre equals 4.046856422 dunams (rounded).

1 acre = 4.046856422 dunams

How to convert acres to dunams

To convert acres to dunams, multiply the number of acres by 4.046856422. The factor is rounded to 10 significant digits. To go the other way, multiply dunams by 0.2471053815 (rounded).

dunams = acres × 4.046856422

Example: 10 acres = 40.46856422 dunams.

About these units

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

Dunam (dunam)

Middle EasternTraditional unit (still used in some regions)

Exactly 1,000 m² in the modern metric standard. Older Ottoman dunams varied by region, from about 900 to 2,500 m².

Ottoman Turkish dönmek means to turn, and the dunam probably follows the Byzantine Greek stremma, a land measure of similar size. Its legal definition was forty standard paces in length and breadth, but the real area differed from province to province, from just over 900 square meters in Ottoman Palestine to about 2,500 in Ottoman Iraq. Roughly it matched the land an ox team could plough in a day.

Today the metric dunam is standardised at exactly 1,000 square meters, a tenth of a hectare, and that is the figure used here. It is the working unit in Israel, Palestine, Syria, Iraq and Turkey, and the Balkan dunam is mostly the same, with local exceptions such as about 1,600 square meters around Leskovac in Serbia. Under the British Mandate the dunam was 919.3 square meters until the metric version was adopted in 1928. Cyprus lists its donum at 1,338 square meters, and the old Ottoman stremma in Greece is given as about 1,270.

1 dunam = 1,000 square meters (exactly).

Sources: Wikipedia: Dunam

Related conversions

See all area units.