Convert Square Hectometer (hm²) to Barn (b (area)) instantly.
About these units
Square Hectometer (hm²)
A square hectometer, equal to 10,000 square meters, is equivalent to a hectare, making it a significant land unit in agriculture, forestry, and environmental planning. While the term "hectare" is far more common, hm² is technically valid within the SI framework and occasionally used in scientific or engineering reports where strict SI formatting is preferred. The unit's scale makes it ideal for measuring fields, park areas, forest plots, and moderate land parcels. Its equivalence to the hectare ensures its place in practical land measurement.
Barn (b (area))
The barn is an area unit used almost exclusively in nuclear and particle physics, equal to 10⁻²⁸ square meters. Despite its incredibly tiny size, the barn emerged from humorous origins: early nuclear physicists joked that certain atomic nuclei were "as big as a barn" compared to the particles trying to hit them. The barn quantifies interaction cross-sections—essentially probabilities of particles colliding or interacting with nuclei. Because fundamental forces operate at extremely small scales, typical cross-section values lie in the microbarn, nanobarn, or picobarn range. The barn is essential for describing reaction rates in particle accelerators, nuclear reactors, and astrophysical processes such as stellar fusion.