Mash Efficiency Calculator

About this calculator

Mash efficiency measures how much of the sugar theoretically available in your grain bill actually made it into the wort, calculated by comparing your measured original gravity and batch volume against the grain’s potential extract (expressed in points per pound per gallon) — a core recipe metric that determines a beer’s final strength and ABV.

All-grain homebrewers use it to fine-tune their process — crush consistency, mash temperature, sparge technique — because a consistent, known efficiency is what lets a brewer hit a target original gravity reliably and scale recipes up or down with confidence.

This calculator takes your measured gravity, batch volume, grain weight and grain potential, and returns your mash efficiency as a percentage.