Beer calories come from two sources: the alcohol itself, and the sugar and dextrins left over after fermentation — which is why two beers at the same ABV can carry different calorie counts if one finished with more residual extract than the other. This site estimates calories using the standard Balling-based homebrew formula, built on the same real-extract terms behind real attenuation, not a simplified alcohol-only shortcut.
Three real examples, low to high
| Beer | OG / FG | ABV (simple) | Calories, 12 oz (355 mL) | Calories, 330 mL |
|---|---|---|---|---|
| Session ale | 1.042 / 1.010 | 4.2% | ~121 kcal | ~112 kcal |
| Standard ale | 1.050 / 1.012 | 5.0% | ~144 kcal | ~134 kcal |
| Imperial stout | 1.090 / 1.020 | 9.2% | ~260 kcal | ~242 kcal |
Check your own OG/FG — every result from the ABV calculator includes both calorie figures alongside ABV and attenuation, computed from the same reading, not a separate lookup.
Why calories don't scale in a straight line with ABV
Notice the imperial stout isn't "twice the ABV, twice the calories" relative to the standard ale — it's roughly 9.2% ABV against 5.0%, a 1.84x jump, against a 1.81x rise in calories. The two ratios sit within a few percent of each other here, and that's a property of this particular set, not a rule: all three examples land within about two points of each other in apparent attenuation (76.0-77.8%), so alcohol and residual extract happen to be scaling together across them. Where calories and ABV genuinely part ways is between two beers that finish at different attenuation for the same alcohol content — one drier, one sweeter — because the unfermented extract left behind carries calories independent of how much alcohol fermentation produced. Two numbers both feed the total: how much alcohol fermentation produced, and how much unfermented extract remains in the glass.
Where this estimate comes from, and its real limits
The formula aggregates Balling-formula calorie calculations as commonly implemented across multiple brewing-software vendors — a reasonable estimate for planning and comparison, not a laboratory nutritional assay. Two beers with identical OG and FG can still differ slightly in real calorie content depending on exactly what sugars and dextrins are present, which this formula can't distinguish from a bare gravity reading alone. Treat these figures the way you'd treat any published homebrew calorie estimate: useful for comparing your own beers to each other and to commercial references, not precise enough for strict dietary tracking.
If you're trying to hit a calorie target, not just check one
Calories track OG and FG together, so the lever that actually reduces them is the same lever that reduces ABV and body: a lower starting gravity, or a mash run to favour a drier, more fermentable finish. See mash temperature and body for how mash temperature shapes fermentability, and what OG do I need for a 6% beer if you're planning backward from a target strength rather than checking a finished batch.