per acre
Number per areaCost per areaexact by definition
The count per acre is exactly 1 ÷ 4046.8564224 per square metre, about 2.471 × 10⁻⁴. North American row crops are planted and counted this way — 32,000 seeds/ac is a normal corn population.
| 1 (Number per area) | 0.00024710538 |
| 1 (Cost per area) | 2.4710538 |
About the per acre
Plant population per acre is the number a planter is set by and a stand is judged against, and it is checked in the field by counting a known fraction of an acre rather than a whole one.
The standard trick is the 1/1000th acre: 43,560 ÷ 1000 = 43.56 square feet. In 30-inch rows that is 17 feet 5 inches of a single row; count the plants along that length, multiply by 1000, and the answer is plants per acre directly.
The row length changes with spacing — 15-inch rows need 34 ft 10 in, 20-inch rows 26 ft 1 in — and getting it wrong scales the whole stand count by the same error.
One plant per acre is 2.471 per hectare, so a 32,000/ac corn population is 79,000/ha.
Cost per acre is exactly 1 ÷ 4046.8564224 of cost per square metre. It is the basis on which North American input costs, custom rates and cash rents are all quoted, and the number a cost-of-production budget is built from.
One per acre in every number per area unit
| 0.000247105 | per square meter (per m²) | |
| 2.47105 | per hectare (per ha) | |
| 1 | per acre (per ac)this unit | |
| 0.0000229568 | per square foot (per ft²) | |
| 0.0229568 | per thousand square feet (per 1000 ft²) |
One per acre in every cost per area unit
| 2.47105 | per hectare ($/ha) | |
| 1 | per acre ($/ac)this unit | |
| 0.000247105 | per square meter ($/m²) | |
| 0.0229568 | per thousand square feet ($/1000 ft²) |