| 0ac | 0ro |
| 1ac | 3.999999479ro |
| 2ac | 7.999998957ro |
| 3ac | 11.99999844ro |
| 4ac | 15.99999791ro |
| 5ac | 19.99999739ro |
| 6ac | 23.99999687ro |
| 7ac | 27.99999635ro |
| 8ac | 31.99999583ro |
| 9ac | 35.99999531ro |
| 10ac | 39.99999479ro |
| 11ac | 43.99999427ro |
| 12ac | 47.99999374ro |
| 13ac | 51.99999322ro |
| 14ac | 55.9999927ro |
| 15ac | 59.99999218ro |
| 16ac | 63.99999166ro |
| 17ac | 67.99999114ro |
| 18ac | 71.99999062ro |
| 19ac | 75.9999901ro |
| 20ac | 79.99998957ro |
| 21ac | 83.99998905ro |
| 22ac | 87.99998853ro |
| 23ac | 91.99998801ro |
| 24ac | 95.99998749ro |
| 25ac | 99.99998697ro |
| 26ac | 103.9999864ro |
| 27ac | 107.9999859ro |
| 28ac | 111.9999854ro |
| 29ac | 115.9999849ro |
| 30ac | 119.9999844ro |
| 31ac | 123.9999838ro |
| 32ac | 127.9999833ro |
| 33ac | 131.9999828ro |
| 34ac | 135.9999823ro |
| 35ac | 139.9999818ro |
| 36ac | 143.9999812ro |
| 37ac | 147.9999807ro |
| 38ac | 151.9999802ro |
| 39ac | 155.9999797ro |
| 40ac | 159.9999791ro |
| 41ac | 163.9999786ro |
| 42ac | 167.9999781ro |
| 43ac | 171.9999776ro |
| 44ac | 175.9999771ro |
| 45ac | 179.9999765ro |
| 46ac | 183.999976ro |
| 47ac | 187.9999755ro |
| 48ac | 191.999975ro |
| 49ac | 195.9999745ro |
| 50ac | 199.9999739ro |
| 51ac | 203.9999734ro |
| 52ac | 207.9999729ro |
| 53ac | 211.9999724ro |
| 54ac | 215.9999719ro |
| 55ac | 219.9999713ro |
| 56ac | 223.9999708ro |
| 57ac | 227.9999703ro |
| 58ac | 231.9999698ro |
| 59ac | 235.9999692ro |
| 60ac | 239.9999687ro |
| 61ac | 243.9999682ro |
| 62ac | 247.9999677ro |
| 63ac | 251.9999672ro |
| 64ac | 255.9999666ro |
| 65ac | 259.9999661ro |
| 66ac | 263.9999656ro |
| 67ac | 267.9999651ro |
| 68ac | 271.9999646ro |
| 69ac | 275.999964ro |
| 70ac | 279.9999635ro |
| 71ac | 283.999963ro |
| 72ac | 287.9999625ro |
| 73ac | 291.9999619ro |
| 74ac | 295.9999614ro |
| 75ac | 299.9999609ro |
| 76ac | 303.9999604ro |
| 77ac | 307.9999599ro |
| 78ac | 311.9999593ro |
| 79ac | 315.9999588ro |
| 80ac | 319.9999583ro |
| 81ac | 323.9999578ro |
| 82ac | 327.9999573ro |
| 83ac | 331.9999567ro |
| 84ac | 335.9999562ro |
| 85ac | 339.9999557ro |
| 86ac | 343.9999552ro |
| 87ac | 347.9999546ro |
| 88ac | 351.9999541ro |
| 89ac | 355.9999536ro |
| 90ac | 359.9999531ro |
| 91ac | 363.9999526ro |
| 92ac | 367.999952ro |
| 93ac | 371.9999515ro |
| 94ac | 375.999951ro |
| 95ac | 379.9999505ro |
| 96ac | 383.99995ro |
| 97ac | 387.9999494ro |
| 98ac | 391.9999489ro |
| 99ac | 395.9999484ro |
The acre is a unit of area and is used in the imperial and US customary systems with the symbol a.
It represents the area the size of one chain by one furlong (66 by 660 feet). This is exactly equal to 10 square chains, 1⁄640 of a square mile or 43,560 square feet.
It is generally used to measure the size of land.
The rood is a unit of area used in historic England with the symbol ro.
Its unit size is equal to 1/4 of an acre, 10,890 ft² or 1,012m². A rectangle equal to one furlong in length and one rod in width is one rood in area.
Its use was very important in surveying land because of the ease of conversion into acres from smaller sections of land.