Calculators

Each page shows the formula, defines its inputs and outputs, walks through a worked example, and provides a table of typical values you can read off directly.

• ABV from OG and FG

  Estimate alcohol by volume from a beer's original and final specific gravity.

  ABV ≈ (OG − FG) × 131.25

• Beer colour (SRM) — Morey formula

  Estimate the colour (SRM) of finished beer from the grain bill and batch volume.

  MCU per grain = (Lovibond × weight_lb) ÷ batch_gal Total MCU = sum of all MCUs SRM = 1.4922 × (Total MCU ^ 0.6859)

• IBU — Tinseth formula

  Predict the bitterness (International Bitterness Units) of beer given hop additions and boil characteristics.

  Utilisation = (1.65 × 0.000125^(SG−1)) × (1 − e^(−0.04 × time)) ÷ 4.15 IBU per addition = (grams × α% × Utilisation × 10) ÷ batch_L

• Mash efficiency

  Calculate the percentage of theoretical sugar yield your mash actually extracted, used to size grain bills for future batches.

  Efficiency_% = (Actual_gravity_points × Batch_volume_gal) ÷ (Sum_of_grain_yield_points) × 100 where each grain contributes: weight_lb × ppg(yield)

• Priming sugar — bottle conditioning

  Calculate the table-sugar (sucrose) addition needed at bottling to reach a target CO₂ carbonation level.

  Residual_CO2 = 3.0378 − (0.050062 × T_F) + (0.00026555 × T_F^2) Sugar_g_per_L = (Target_vols − Residual_CO2) × 4 where T_F is fermentation temperature in °F (use highest temp the beer reached after primary).

• Strike water temperature

  Calculate how hot to heat your mash water so that adding grain at room temperature lands you at the target mash temperature.

  Strike_T = (0.41 × (T_target − T_grain) ÷ R) + T_target where R = water-to-grain ratio (L water per kg grain), and 0.41 is the heat-capacity ratio between water and grain.