liminfoHomebrew Calculator
Free web tool: Homebrew Calculator
Alcohol By Volume
5.25%
About Homebrew Calculator
The Homebrew Calculator is a four-in-one brewing tool that covers the most critical calculations in homebrewing: Alcohol By Volume (ABV), International Bitterness Units (IBU), Standard Reference Method color (SRM), and priming sugar for bottle carbonation. Each calculation has its own dedicated tab so you can focus on the metric you need without cluttering the interface.
The ABV tab uses the industry-standard simplified formula: (OG − FG) × 131.25. Enter your original gravity (OG) and final gravity (FG) measured by hydrometer or refractometer after fermentation to instantly know the alcohol content of your batch. The IBU tab implements the Tinseth utilization model — the most widely used homebrew bitterness formula — which accounts for alpha acid percentage, hop weight in grams, boil time in minutes, batch volume in liters, and wort gravity. The SRM tab applies the Morey equation using grain weight (kg), Lovibond color rating, and batch volume to predict the final beer color.
The Priming tab calculates the exact amount of priming sugar (table sugar or corn sugar/dextrose) needed to achieve a target CO2 volume level in your finished beer. It accounts for residual CO2 already dissolved in the beer at fermentation temperature using a temperature-correction polynomial. All four calculations run entirely in your browser — no account, no install, no data sent to any server.
Key Features
- ABV calculation using (OG − FG) × 131.25 standard formula
- IBU calculation using the Tinseth utilization model with alpha acid, boil time, and wort gravity
- Hop utilization percentage displayed alongside IBU for recipe optimization
- SRM beer color prediction using the Morey equation from grain weight and Lovibond rating
- Priming sugar calculator for both table sugar and corn sugar (dextrose)
- Temperature-corrected residual CO2 calculation for accurate carbonation targeting
- Shared batch volume input carries across IBU, SRM, and priming tabs
- Tab-based interface with dark mode, bilingual Korean/English support, and mobile layout
Frequently Asked Questions
How is ABV calculated?
ABV is calculated using the formula (OG − FG) × 131.25, where OG is the original gravity before fermentation and FG is the final gravity after fermentation completes. For example, OG 1.050 and FG 1.010 gives (1.050 − 1.010) × 131.25 = 5.25% ABV.
What is the Tinseth IBU formula?
The Tinseth model calculates IBU as: (alpha acid% ÷ 100) × hop weight (g) × utilization × 1000 ÷ batch volume (L). Utilization depends on boil time and wort gravity. Higher gravity wort and shorter boil times reduce utilization, yielding fewer IBUs from the same amount of hops.
What is a good IBU level for different beer styles?
Light lager: 8–15 IBU. Pale ale: 30–50 IBU. IPA: 50–80 IBU. Imperial IPA: 60–100+ IBU. Stout: 25–45 IBU. The perceived bitterness also depends on the beer's sweetness (final gravity) — a higher FG beer tastes less bitter at the same IBU.
How does the SRM color calculation work?
SRM is calculated using the Morey equation: 1.4922 × MCU^0.6859, where MCU (Malt Color Units) = grain weight (lbs) × Lovibond ÷ batch volume (gal). The calculator handles the unit conversions from kg and liters automatically.
What SRM value corresponds to which beer color?
SRM 1–3: pale straw (pilsner). SRM 4–7: gold (pale ale). SRM 8–14: amber (amber ale, märzen). SRM 15–22: copper/brown (brown ale). SRM 23–35: dark brown (porter). SRM 35+: black (stout, schwarzbier).
How much priming sugar do I need?
The amount depends on your target CO2 volumes, fermentation temperature, and batch size. The calculator uses target CO2 volume minus residual CO2 (determined by temperature) to find the net CO2 needed, then converts that to grams of table sugar or corn sugar.
Why does fermentation temperature affect priming sugar?
CO2 is more soluble in cold liquid than warm liquid. Beer fermented at a lower temperature retains more residual CO2. Adding the same amount of priming sugar to cold-fermented beer as to room-temperature beer would over-carbonate it. The calculator corrects for this automatically.
What is the difference between table sugar and corn sugar for priming?
Table sugar (sucrose) is 100% fermentable and requires about 4 g per liter per CO2 volume unit. Corn sugar (dextrose/glucose) is slightly less dense and requires about 4.59 g per liter per unit. Both work equally well — corn sugar is preferred by some brewers because it does not introduce any off-flavors during conditioning.