Area units calculator & converter tool
Acre Conversions Table
Equivalent of 4 Acre: |
16187.450678861 m2 (Square meter) |
161874506.78861 cm2 (Square centimeter) |
1618745.0678861 dm2 (Square decimeter) |
16187450678.861 mm2 (Square milimeter) |
0.016187450678861 km2 (Square Kilometer) |
1.6187450678861 Hectare |
161.87450678861 Are |
16.187450678861 Decare |
16187.450678861 Centiare |
4.7349102608203 Arpent |
16187450.678861 Barn |
174240.10036219 Square feet |
640.00161874507 Square perche |
0.0062499747071083 Square mil |
19360.029137411 Square yard |
25090623.461221 Square inch |
0.00017369134578418 Canton |
0.024993423848162 Homestead |
15.999676250986 Rood |
Acre / Barn Units Definition
Acre
The acre (/ˈeɪkər/ AY-kər) is a unit of land area used in the British imperial and the United States customary systems. It is traditionally defined as the area of one chain by one furlong (66 by 660 feet), which is exactly equal to 10 square chains, 1⁄640 of a square mile, 4,840 square yards, or 43,560 square feet, and approximately 4,047 m2, or about 40% of a hectare. Based upon the international yard and pound agreement of 1959, an acre may be declared as exactly 4,046.8564224 square metres. The acre is sometimes abbreviated ac but is usually spelled out as the word "acre".
Barn
A barn (symbol: b) is a metric unit of area equal to 10-28 m2 (100 fm2). Originally used in nuclear physics to express the cross section of nuclei and nuclear reactions, it is also used today in all areas of high energy physics to express the cross sections of any diffusion process, and is best understood as a measure of the probability of interaction between small particles. A barn corresponds approximately to the cross section of a uranium nucleus. The barn is also the unit of area used in nuclear quadrupole resonance and nuclear magnetic resonance to quantify the interaction of a nucleus with an electric field gradient. Although the barn was never an SI unit, the SI standards body recognized it in the 8th SI brochure (replaced 2019) due to its use in particle physics.