IBU and Hop Bitterness

Excel Formulas › Food Truck & Brewery

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IBU (International Bitterness Units) estimates a beer’s bitterness from hop alpha acids, amount, utilization, and batch volume — the recipe math behind a hoppy or balanced beer.

Quick formula: IBU from a hop addition:
=alpha_acid * oz * utilization * 7489 / volume_gal
Alpha-acid % times ounces times utilization times a unit constant, over gallons, gives the addition's IBUs.

The example

12% AA, 1.5 oz, 25% util, 5 gal.

AB
1ItemValue
2Tinseth-style estimate—
3IBU→ ~67

The formula

The formula:

=alpha_acid_decimal * oz * utilization * 7489 / volume_gal // AA × oz × util × 7489 ÷ gallons

How it works

How it works:

  1. Alpha acid (as a decimal, 0.12 for 12%) is the hop’s bittering potential.
  2. Multiply by ounces, utilization (boil-time dependent), and the unit constant 7489.
  3. Divide by batch gallons for the addition’s IBUs; sum all additions for total IBU.
  4. Higher gravity lowers utilization — big beers extract less bitterness per hop.

Utilization is where IBU estimates live or die. The same hop gives very different bitterness depending on boil time (longer = more) and wort gravity (higher = less), captured by the utilization factor. The 7489 constant just converts ounces, gallons, and percent into IBU units (it’s the imperial form of the Tinseth math). Sum every addition’s IBUs for the recipe total, and remember it’s an estimate — taste confirms.

Try it: interactive demo

Live demo

Alpha acid %, ounces, utilization %, gallons.

IBU:

Variations

Total IBU

Sum additions:

=SUM(per_addition_ibu)

BU/GU ratio

Balance:

=total_ibu / (OG_points)

Hops for a target IBU

Solve for oz:

=target_ibu * volume / (alpha*util*7489)

Pitfalls & errors

Alpha as decimal. 12% is 0.12 in the formula.

Utilization varies. Boil time and gravity change it — use a chart.

Estimate only. IBU is a model — taste is the final judge.

Practice workbook

📊
Download the free IBU and Hop Bitterness practice workbook
An IBU sheet with the total, BU/GU, and target-hop variants, plus 4 challenges with answers. No sign-up required.

Frequently asked questions

How do I calculate IBU in Excel?
Alpha × oz × utilization × 7489 / gallons: =alpha_acid_decimal * oz * utilization * 7489 / volume_gal. Sum all additions for total IBU.
What's utilization?
The fraction of hop bitterness extracted, depending on boil time and wort gravity.
How many hops for a target IBU?
=target_ibu * volume / (alpha*util*7489).

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