Calculate International Bitterness Units for your beer recipe using the Tinseth formula. Add multiple hop additions to see per-addition and total IBU.

How It Works

This calculator uses the Tinseth method, the most widely used formula for estimating IBU in homebrewing. The calculation accounts for two key factors:

Bigness factor: Higher gravity wort reduces hop utilization. Formula: 1.65 × 0.000125^{(SG − 1)}
Boil time factor: Longer boil times extract more bitterness, with diminishing returns. Formula: (1 − e^{−0.04 × time}) / 4.15

The utilization (bigness × boil time factor) is then applied: IBU = (utilization × alpha/100 × weight_mg) / volume_L

Bitterness guide: <20 IBU = Low (wheats, lagers), 20–40 = Moderate (pale ales), 40–60 = Assertive (IPAs), 60+ = Very Bitter (DIPAs).

IBU Calculator (Tinseth Method)

Batch Parameters

Hop Additions

Results

How It Works