Beer Recipe Calculator - OG, FG, ABV, and SRMv1.0.0

A grain bill, batch volume, efficiency, and yeast attenuation are enough to predict original gravity (OG), final gravity (FG), alcohol by volume (ABV), beer color in SRM and EBC, calories, and Plato readings before brew day. The calculator supports all-grain, brew-in-a-bag (BIAB), extract, and partial mash methods. Select a unit system and brew method, enter your batch parameters, and build your grain bill. Two ABV formulas are available: the standard formula suitable for most common beers, and the more accurate Hall Equation 16 formula recommended for high-gravity brews. Three color estimation methods (Morey, Daniels, and Mosher) let you cross-reference SRM predictions.

• Select US or Metric units at the top. All weight and volume labels update automatically.
• Choose your Brew Method (All Grain, BIAB, Extract, or Partial Mash). The default efficiency adjusts accordingly.
• Enter your Batch Size (post-boil volume into the fermenter) and Pre-Boil Volume.
• Set your Brewhouse Efficiency as a percentage. Typical values range from 65% for BIAB to 80% for experienced all-grain brewers.
• Click Add Fermentable to build your grain bill. Select a grain from the dropdown or type a custom name. Enter the weight, PPG (points per pound per gallon), and Lovibond color rating. The tool includes a built-in database of common malts that auto-fills PPG and Lovibond values when selected.
• Set your Yeast Attenuation using a preset (Low 66%, Medium 75%, High 77%) or enter a custom value. This percentage determines how much sugar the yeast will consume.
• Click Calculate or allow the 500-millisecond auto-calculate debounce to update results. The results table displays OG, FG, ABV, SRM, EBC, color preview, apparent and real attenuation, calories per 12-ounce serving, and Plato readings for both OG and FG.
• Open Settings to switch between the simple and advanced ABV formulas, choose a color estimation method, or enable step-by-step calculation breakdowns.
• Click Reset to clear all entries and restore defaults. All inputs persist in your browser between sessions via localStorage.

Predicting OG, FG, ABV, and color from an ingredient list turns recipe design into an iterative process, where grain quantities can be adjusted to hit a target before any ingredients are purchased. The same calculation covers a light session ale and a high-gravity imperial stout, changing only the inputs.

• All-Grain Recipe Design: Enter your full grain bill with mash efficiency to predict OG before purchasing ingredients. Adjust grain quantities until the gravity target matches your chosen beer style guidelines.
• Extract Brewing: Switch to extract mode and enter liquid or dry malt extract weights. The calculator accounts for the higher extraction efficiency of pre-made extracts to deliver accurate gravity estimates.
• BIAB Planning: Use the BIAB method preset with its lower default efficiency to get realistic gravity predictions for brew-in-a-bag setups without a separate sparge step.
• Color Estimation: Compare SRM values across Morey, Daniels, and Mosher methods. Verify that your grain bill produces the color range expected for your target style, from light pilsner gold to opaque stout black.
• High-Gravity Accuracy: Switch to the advanced Hall ABV formula in settings when brewing barleywines, Belgian quads, or imperial stouts where the simple formula underestimates alcohol content.
• Recipe Scaling: Adjust batch size and pre-boil volume to scale recipes up or down. The percentage column in the grain bill helps maintain correct ratios when changing total weight.
• Yeast Selection: Compare how different yeast attenuation levels affect final gravity and ABV. Test low, medium, and high attenuation scenarios to choose the right yeast strain for your desired flavor profile and alcohol level.
• Education: Enable step-by-step calculations to understand how gravity points, efficiency, and attenuation interact. Useful for new brewers learning the science behind recipe formulation.