What you need: The same two hydrometer readings you already take for ABV — Original Gravity (OG) before fermentation and Final Gravity (FG) after. Don't have a hydrometer and trial jar yet? They're essential kit for this and most other calculators on this site.

Calories come from two sources: the alcohol produced during fermentation, and the residual (unfermented) extract left behind in the finished beer. This calculator estimates both from your gravity readings using the standard homebrew approximation.

Note: This is a widely-used estimate (the same method behind our ABV calculator's calorie figure) — it doesn't account for unfermentable sugars from adjuncts like lactose or maltodextrin, which will make the true figure higher than shown here.