Select a category
Conversion Formula:
Convert Barn to Perch (b to perch) instantly with accurate, readable results.
Convert between square meters, acres, square feet, hectares, and other common units with our Area Unit Converter. This intuitive unit conversion tool helps you calculate land size, floor space, and surface area across both metric and imperial systems. Whether you're working on real estate, construction, or geography tasks, our area unit conversion calculator ensures precise and instant results.
Barn (b) - nuclear/particle cross-section area
Barn is a non-SI unit of area used in nuclear and particle physics to express interaction cross-sections. The name originated humorously during the Manhattan Project (“as big as a barn”).
- Symbol: b
- System: Non-SI (accepted in high-energy/nuclear physics)
- Exact relations: 1 b = 10⁻²⁸ m² = 10⁻²⁴ cm² = 100 fm²
- Common submultiples: 1 mb = 10⁻³ b; 1 µb = 10⁻⁶ b; 1 nb = 10⁻⁹ b; 1 pb = 10⁻¹² b; 1 fb = 10⁻¹⁵ b; 1 ab = 10⁻¹⁸ b
- Related usage: integrated luminosity often quoted in inverse barns (e.g., fb⁻¹)
- Typical examples: neutron capture and scattering cross-sections; collider process cross-sections reported from barns down to picobarns and femtobarns
Perch (square perch, square rod, pole, lug) - traditional land area
Perch is a historical Imperial/US customary unit of area equal to one square rod. Used in older cadastral records and property descriptions alongside roods and acres.
- Symbol: none standardized (written as “perch”, “sq perch”, or “square rod”)
- System: Imperial/US customary (historic)
- Exact relations: 1 perch = 1 square rod = (16.5 ft)² = 272.25 ft² = (5.0292 m)² = 25.29285264 m²
- Other relations: 40 perches = 1 rood; 160 perches = 1 acre; 16 perches = 1 square chai
- Typical examples: plot descriptions such as “2 roods 13 perches”; 19th-century deeds and survey plans