A barn is a nuclear cross-section unit equal to 1e-28 square meters.
Barns to Square Femtometers Converter — b to fm2
Convert Barn (b) to Square Femtometer (fm2) using the exact conversion factor (1 barn = 100 square femtometer). See the formula, worked examples, and conversion table.
Barns to Square Femtometers converter
Converter
Area Converter
Convert land, construction, mapping, survey, and scientific area units.
Context values
Some unit families need one extra value for a physically accurate result.
Square metric area unit.
Result = input x 1e-28 / 1e-30.
Area uses the square meter as the base unit.
Reserved above the conversion cards and below the converter.
About Converting Barns to Square Femtometers
Comparing Barn and Square Femtometer is common in agriculture and real estate, where US land is typically measured in acres and most of the rest of the world uses hectares. Specifically: A barn is a nuclear cross-section unit equal to 1e-28 square meters, and square metric area unit.
Formula
square femtometers = barns × 100
This factor comes from each unit's defined relationship to the category's base unit: 1 barn equals 1e-28 base units, and 1 square femtometer equals 1e-30 base units, so dividing one by the other gives the direct barn-to-square femtometer factor of 100.
Simple example
1 b × 100 = 100 fm2
1 barn = 100 square femtometers.
Real-world example
10 b × 100 = 1,000 fm2
10 barns = 1,000 square femtometers.
Conversion table
| Barn (b) | Square Femtometer (fm2) |
|---|---|
| 1 b | 100 fm2 |
| 5 b | 500 fm2 |
| 10 b | 1,000 fm2 |
| 25 b | 2,500 fm2 |
| 50 b | 5,000 fm2 |
| 100 b | 10,000 fm2 |
Reverse conversion: Square Femtometer to Barn
100 fm2 × 0.01 = 1 b
100 square femtometers = 1 barns.
barns = square femtometers × 0.01
For a page dedicated to this direction, see Square Femtometer to Barn.
Understanding the Barn (b)
A barn is a nuclear cross-section unit equal to 1e-28 square meters.
Understanding the Square Femtometer (fm2)
Square metric area unit.
Reserved between the cards and the FAQ so the page stays balanced.
Frequently asked questions
How many square femtometers are in 1 barn?
1 barn equals 100 square femtometers, using the exact defined conversion factor rather than an estimate.
How do I convert barn to square femtometer?
Multiply the barn value by 100. The converter above does this instantly to whatever precision you set.
How do I convert square femtometer back to barn?
Use the reverse factor: 1 square femtometer equals 0.01 barns. You can also use the swap control in the converter above to flip the direction instantly.
What is a barn?
Barn (b) is a unit of area.
What is a square femtometer?
Square Femtometer (fm2) is a unit of area.
Is the barn to square femtometer conversion exact?
Yes. Both barn and square femtometer are defined by fixed standards rather than physical artifacts, so the factor of 100 used above is exact to as many digits as you choose to display.