Homebrewer's Recipe Calculator
Add your malts and hops and see how strong, bitter, and dark your beer will be - updated live as you type. Compare your recipe to recognised style categories and map your brew day with visual charts. Everything runs in your browser, nothing uploaded.
Grain Bill Breakdown
Add grains to see breakdown
Hop Schedule
Add hop additions to see schedule
BJCP Style Match
Add grains and hops to see style match
Learn more: homebrew recipe calculation
How homebrewing formulas work - OG, FG, IBU and SRM
Original Gravity (OG) measures the sugar content of your wort before fermentation. Final Gravity (FG) measures residual sugar after the yeast finishes. ABV is calculated as (OG - FG) × 131.25. IBU (International Bitterness Units) comes from hop additions and is calculated using the Tinseth formula, accounting for boil time, hop alpha acid percentage, and isomerization. SRM (Standard Reference Method) measures beer color from 1 (pale straw) to 40+ (opaque black), derived from grain selection using the Morey formula.
From grain bill to finished beer - the mash and boil process
Add malts and their quantities to create your grain bill - the malt breakdown chart shows the percentage contribution by weight. Mash efficiency (typically 75%) converts grain sugar into fermentable wort. Hop additions at various boil times contribute both bitterness (IBU) and aroma. Use 0 minutes for flameout and whirlpool additions - dry hops (post-fermentation) don't contribute IBU. After boil, yeast attenuation (how much sugar the yeast consumes) determines your final gravity and alcohol content.
BJCP style matching and recipe validation
The Beer Judge Certification Program defines 22 recognised beer style categories used in homebrew competitions worldwide. This calculator compares your recipe's OG, FG, ABV, IBU, and SRM against each style's target range and shows you the closest match. The BU:GU ratio (Bitterness Units to Gravity Units) balances perceived bitterness with malt sweetness - a ratio above 1.0 tastes more bitter, below 1.0 tastes more malty. Staying within BJCP guidelines helps your beer perform well in competitions and ensures it matches what drinkers expect from that style.
FAQ
Can I save my recipes locally?
Yes. Recipes save to your browser's localStorage with no account or signup needed. You can save up to 20 recipes. Export as BeerXML format to use in BeerSmith, BrewFather, or other homebrewing software, or import BeerXML files back into this calculator.
What is mash efficiency and why does it matter?
Mash efficiency (typically 60-80%) is the percentage of grain's potential sugar that converts to fermentable wort. Factors include grain crush, mash temperature, and sparge technique. Higher efficiency (75%+) means you extract more sugar with less grain, reducing cost and time.
How do I know if my recipe is balanced?
Check the BU:GU ratio. A ratio near 1.0 balances bitterness with malt sweetness. IPAs (60+ IBU) typically have 0.8-1.2 BU:GU; cream ales (5-12 IBU) stay below 0.5. A good style match in BJCP categories confirms your recipe numbers fit a recognised beer type.