This checker compares your recipe’s vital statistics against the official BJCP 2021 ranges for a chosen style — the exact OG, FG, IBU, ABV, and SRM windows a competition judge uses. Enter your numbers and each is flagged in-range or out-of-range with the target.
How it works
Every BJCP style defines five vital-statistic ranges:
- OG — original gravity, the sugar present before fermentation.
- FG — final gravity, the sugar remaining after fermentation.
- IBU — International Bitterness Units.
- ABV — alcohol by volume, as a percentage.
- SRM — Standard Reference Method colour.
The tool stores the low and high bound for each statistic per style. For each
value you enter, it simply tests whether low ≤ value ≤ high. If a value sits
outside the window, it is flagged, and the target range is shown so you know
which direction to adjust.
Worked example
For an American IPA (BJCP 21A), the guideline ranges are roughly OG 1.056–1.070, FG 1.008–1.014, IBU 40–70, ABV 5.5–7.5%, SRM 6–14. A recipe at OG 1.062, FG 1.012, IBU 55, ABV 6.6%, SRM 9 lands cleanly inside every window — it is to style. Push the IBU to 80 and the checker flags bitterness as too high for 21A, hinting at a Double IPA instead.
Tips and notes
- ABV is derived from OG and FG:
ABV ≈ (OG − FG) × 131.25. If your ABV looks off, re-check your gravity readings first. - Colour (SRM) is the most commonly missed range — a single dark specialty malt can push a pale style out of bounds. The grain bill optimizer helps you target SRM precisely.
- Being one or two points outside a range is rarely fatal in judging; a beer that is clearly the wrong colour or strength for the declared style is.
- Use this before you brew to sanity-check a recipe, and again after fermentation with measured gravities before you enter a competition.