Area units calculator & converter tool
Km2 Conversions Table
Equivalent of 18 km2 (Square Kilometer): |
18000000 m2 (Square meter) |
180000000000 cm2 (Square centimeter) |
1800000000 dm2 (Square decimeter) |
18000000000000 mm2 (Square milimeter) |
1800 Hectare |
180000 Are |
18000 Decare |
18000000 Centiare |
5265.09 Arpent |
18000000000 Barn |
193750200 Square feet |
4447.89 Acre |
711664.2 Square perche |
6.9498 Square mil |
21527820 Square yard |
27900083296.733 Square inch |
0.19314 Canton |
27.792 Homestead |
17791.2 Rood |
Km2 / Barn Units Definition
km2 (Square Kilometer)
The square kilometer (km2) is a unit of measurement of area. One square kilometer is equal to the area of a square whose sides measure one kilometer.
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.