## Measurement unit: barn

**Full name:** barn

**Plural form:** barns

**Symbol:** bn

**Category type:** area

**Scale factor:** 1.0E-28

## SI unit: square meter

The SI derived unit for area is the square meter.

1 square meter is equal to 1.0E+28 barn.

Valid units must be of the **area** type.

You can use this form to select from known units:

## Definition: Barn

A barn is a unit of area, abbreviated mostly as "bn", equal to 10^{-28} m^{2}. Although not an official SI unit, it is widely used by nuclear physicists, since it is convenient for expressing the cross sectional area of nuclei and nuclear reactions. A barn is approximately equal to the area of a uranium nucleus.

## Sample conversions: barn