Square Foot (US Survey) to Barn Converter
Unit Converter
Instant · Precise · Universal
23 units available
6 categories total
How to Convert Square Foot (US Survey) to Barn
To convert US survey ft² to m²: multiply by 0.09290341. To international ft²: multiply by ~1.000004.
1 ft² (US) ≈ 0.09290341 m². Differs from international ft² (0.09290304 m²) by about 4 × 10⁻⁷ m².
For example, 1 Square Foot (US Survey) (ft² (US)) = 9.290341e+26 Barn (b).
Square Foot (US Survey) to Barn — Common Values
| Square Foot (US Survey) (ft² (US)) | Barn (b) |
|---|---|
| 0.1 | 9.290341e+25 |
| 0.5 | 4.645171e+26 |
| 1 | 9.290341e+26 |
| 2 | 1.858068e+27 |
| 5 | 4.645171e+27 |
| 10 | 9.290341e+27 |
| 25 | 2.322585e+28 |
| 50 | 4.645171e+28 |
| 100 | 9.290341e+28 |
| 500 | 4.645171e+29 |
| 1000 | 9.290341e+29 |
About Square Foot (US Survey) (ft² (US))
Definition
The US survey square foot is a historical area unit based on the US survey foot (1200/3937 m), equal to approximately 0.09290341 m².
Mathematical Relationship
1 ft² (US) ≈ 0.09290341 m². Differs from international ft² (0.09290304 m²) by about 4 × 10⁻⁷ m².
Conversion Formula
To convert US survey ft² to m²: multiply by 0.09290341. To international ft²: multiply by ~1.000004.
Practical Applications
Historical property records and government land survey documents.
Interesting Facts
The difference from the international square foot is only about 0.4 mm² — negligible for a single measurement, but significant over millions of square feet.
Common Mistakes
Using the US survey foot in new work. Since 2023, only the international foot is valid in the US.
Educational Tips
The US survey foot existed because of a historical definition difference. It's now retired — use the international foot (exactly 0.3048 m).
About Barn (b)
Definition
The barn is a unit of area equal to 10⁻²⁸ m², used to express nuclear cross-sections — the effective target area of subatomic particles.
Mathematical Relationship
1 b = 10⁻²⁸ m² = 100 fm². Millibarns (mb), microbarns (µb), and nanobarns (nb) are common submultiples.
Conversion Formula
To convert barns to m²: multiply by 10⁻²⁸. To fm²: multiply by 100.
Practical Applications
Quantifying nuclear reaction probabilities, neutron absorption, and particle scattering in reactor design.
Interesting Facts
The physicists named it 'barn' as a joke: nuclei were 'as big as a barn' compared to what they expected. Later units include 'outhouse' (10⁻⁶ barns) and 'shed' (10⁻²⁴ barns).
Common Mistakes
Thinking a barn is a large area — at the human scale 10⁻²⁸ m² is incomprehensibly small.
Educational Tips
Cross-section = probability of interaction. A bigger barn value means a particle is more likely to 'hit the target' — hence the barn analogy.