Boil-Off Rate Calculator

Determine your kettle evaporation rate and plan pre-boil volumes accurately

Total wort volume before the boil begins.
gal
Volume remaining after the boil, before transfer.
gal
Duration of the boil in minutes. Standard is 60.
min
Inner diameter of your kettle. Wider kettles evaporate faster.
in

Results

Boil-Off Rate:-gal/hr
Evaporation % per Hour:-%
Boil-Off per Minute:-gal/min
Estimated Loss (60 min):-gal
Estimated Loss (90 min):-gal
Reference: Typical homebrew boil-off rates range from 0.5 to 1.5 gal/hr depending on kettle geometry and heat source.