CalculateTinseth estimate
IBU Calculator
Free IBU calculator using the Tinseth formula. Enter hop weight, alpha acid, boil time, batch volume, and gravity to estimate bitterness.
Estimate International Bitterness Units (IBU) from your hop additions using the Tinseth formula.
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How the IBU Calculator works
International Bitterness Units (IBU) quantify the bitterness contributed by hops. This calculator uses the Tinseth model, which estimates how much of each addition's alpha acids are isomerised based on boil time and wort gravity.
Higher-gravity worts extract bitterness less efficiently, and longer boils extract more, up to a plateau. Add one row per hop addition to see both each addition's contribution and the total.
Frequently asked questions
- Which IBU formula does this use?
- It uses the Tinseth utilization model, the most common formula for estimating IBU from hop additions.
- Why does gravity affect IBU?
- Denser wort isomerises alpha acids less efficiently, so the same hops in a stronger wort yield fewer IBUs.
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