What is acre?
An acre is a unit of area in imperial and US customary systems equal to 43,560 square feet. It is the standard unit for measuring agricultural land, property lots, and parks in the United States and United Kingdom.
Real-world uses
Acres are used for land parcels, farm sizes, and real estate in the US, UK, and some Commonwealth countries. Zoning laws often specify minimum lot sizes in acres. An American football field (including end zones) is about 1.32 acres.
History
The acre originated in medieval England as the amount of land a yoke of oxen could plough in one day. The word comes from Old English "æcer." It was standardized as a strip 1 furlong (660 ft) by 1 chain (66 ft), yielding 43,560 square feet.
Common mistakes
Assuming an acre is a square measure with specific dimensions—it is 43,560 sq ft but can be any shape. Also, confusing acres with hectares: 1 acre ≈ 0.405 hectares, so roughly 2.5 acres make one hectare.
What is square centimetre?
A square centimetre is a metric unit of area equal to one ten-thousandth of a square metre. It is used in textiles, printing, medical surface measurements, and small-scale technical applications.
Real-world uses
Square centimetres are used for cross-sectional areas of cables and pipes, skin wound sizes in medicine, and stamp collecting. PCB (printed circuit board) dimensions and bandage sizes are often specified in cm².
History
The square centimetre was the base area unit in the CGS system and was widely used in physics before SI standardization. It remains commonly used in everyday contexts where square metres are too large a unit for practical description.
Common mistakes
Confusing cm² with mm²—there are 100 mm² in 1 cm², not 10. This is a common error when converting between metric area units because area scales as the square of the linear conversion factor.
When is this conversion used?
Converting between acre and square centimetre is common when working across metric and imperial systems, such as international trade, travel between countries with different measurement standards, or following instructions from a different region.
Worked examples
1 acre = 40,468,564.224 square centimetre
1 square centimetre = 0.0001 square metre
How to convert acre to square centimetre
To convert acre to square centimetre, multiply the value by 40,468,564.224.
To convert square centimetre back to acre, multiply by 2.471054e-08.
Measurement standards
The square metre is the SI derived unit of area. The hectare (10,000 m²) is accepted for use with the SI by the BIPM, particularly for land measurement, though it is not an SI unit itself.
Did you know?
Vatican City, the world's smallest independent state, covers just 0.44 km² (about 109 acres) — smaller than many golf courses. By contrast, Russia spans over 17.1 million km², nearly 39 million times larger.
Quick reference: acre to square centimetre
| acre | square centimetre |
|---|---|
| 0.1 | 4,046,856.4224 |
| 0.5 | 20,234,282.112 |
| 1 | 40,468,564.224 |
| 2 | 80,937,128.448 |
| 5 | 202,342,821.12 |
| 10 | 404,685,642.24000001 |
| 25 | 1.011714e+09 |
| 50 | 2.023428e+09 |
| 100 | 4.046856e+09 |
| 250 | 1.011714e+10 |
| 500 | 2.023428e+10 |
| 1,000 | 4.046856e+10 |
Common values
| acre | square centimetre | |
|---|---|---|
| A4 paper | 0.00001532 acre | 620 square centimetre |
| Parking space | 0.00308882 acre | 125,000 square centimetre |
| Tennis court | 0.06446238 acre | 2,608,700 square centimetre |
| Football field (soccer) | 1.76433242 acre | 71,400,000 square centimetre |
| Central Park, NYC | 842.6293508 acre | 3.410000e+10 square centimetre |