The Prout is an obsolete unit of energy, whose value is:

${\displaystyle 1Prout=2.9638\times 10^{-14}J}$

This is equal to one twelfth of the binding energy of the deuteron.

The "Prout" is a unit of nuclear binding energy, and is 1/12 the binding energy of the deuteron, or 185.5 keV.

This unit is named after William Prout, who first proposed a quantum of mass.

"Proutons" was an early candidate for the name of what are now called protons.^{[citation needed]}

This unit was used in the mid-19th century by several physicists, including Marignac, who first proposed it in 1844.