Hop additions
How to use this calculator
Enter the wort volume, wort gravity, hop weight, alpha acid percentage and boil time. Weight means grams of hops; alpha acid is the percentage printed on the packet or lot label. Volume should be the wort volume associated with the addition.
The public page models one pellet boil addition. Use a separate calculation for each addition and combine the results when planning a schedule. Whirlpool and dry-hop additions require the full Beer Control tool.
How the calculation works
The calculation is performed by the same hop-analysis engine used by Beer Control. It applies the project's gravity, boil-time and pellet-hop utilization model, then derives estimated IBU from hop mass, alpha acid and wort volume.
This is a planning estimate. It does not claim that every hop, kettle geometry or break condition behaves identically. The full calculator adds recipe context and supports more addition types; this public page deliberately keeps the inputs standalone.
Example calculation
For 20 L of wort at 1.050, 30 g of 10% alpha-acid pellet hops and 60 minutes, the shared Beer Control engine returns approximately 42 IBU.
Understanding the result
IBU is an estimate of iso-alpha acid concentration, not a complete measurement of perceived bitterness. Residual sweetness, alcohol, water sulfate, roast character, yeast and hop aroma all affect how bitter a beer feels.
Use the result to compare recipe options and keep brew-day targets consistent. A measured laboratory IBU can differ from a model estimate, especially when the actual volume, gravity or hop utilization differs from the assumptions.
Common mistakes
- Confusing alpha acid percentage with hop weight.
- Using a volume that does not match the modeled wort stage.
- Treating dry hopping as a normal boil addition.
- Combining additions without calculating each boil time separately.
Frequently asked questions
What does IBU mean?
IBU means International Bitterness Unit and is used as an estimate of iso-alpha acid concentration.
Does dry hopping add the same bitterness as boiling?
No. Dry hopping is primarily an aroma technique and should not be entered as a normal boil addition in this calculator.
Why can two IBU calculators disagree?
They may use different utilization models, volumes, gravity corrections, hop assumptions or treatment of late additions.
Related brewing guides
Related tools
This public tool
A quick, free, no-login estimate for a single calculation — nothing is saved.
Inside Beer Control
The same calculation stays linked to your recipe, ingredients, equipment and brew session, so targets and measured values travel together through the whole workflow.
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