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Recipe

Bitterness to gravity ratio (BU:GU)

40 IBU on a 1.040 beer is not the same beer as 40 IBU on a 1.080. The BU:GU ratio measures that balance.

Above 1.000.

Result

Fill in the values and run the calculation, or try the example.

This is the calculation Krausi uses. Create an account to save it in a recipe or a brew.

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Why look at the BU:GU ratio?

IBUs alone do not tell you whether a beer will taste bitter. Bitterness is perceived against the sweetness of the malt: 40 IBU dominate a light beer and go almost unnoticed in a strong one.

The BU:GU ratio divides the bitterness units (BU) by the gravity points (GU). A single number sums up the balance: around 0.5 the beer is balanced, below 0.4 it leans towards malt, above 0.8 the bitterness is clear.

It is the right reflex when you change a recipe: if you raise the gravity, raise the hops to keep the same ratio.

How is the BU:GU ratio calculated?

The calculation is a simple division:

BU:GU = IBU / ((OG − 1) × 1000)

A beer at 40 IBU with an original gravity of 1.050 has a ratio of 0.80. The same bitterness on a beer at 1.080 gives 0.50.

Benchmarks given by the tool: below 0.4, a malty beer; around 0.5, balanced; above 0.8, clearly bitter.

Worked example

Values entered

  • Bitterness in IBU: 40
  • Original gravity as decimal SG: 1.05

Result from the tool

BU:GU ratio
0.8
How to read it
< 0.4: malty; ≈ 0.5: balanced; > 0.8: clearly bitter

What the tool does not do

  • The ratio ignores the final gravity: a very dry beer tastes more bitter than a full-bodied one at the same ratio.
  • It says nothing about aroma: a massive dry hop does not change the number.
  • The benchmarks are habits, not style rules.

Frequently asked questions

What BU:GU ratio for a blonde?

Between 0.4 and 0.6 for a blonde or a pils. A wheat beer goes down to 0.3, a pale ale up to 0.7.

Is my IPA bitter enough?

An IPA sits between 0.8 and 1.0, sometimes more. At an original gravity of 1.060, that is 50 to 60 IBU.

And with the assistant?

Ask Krausi the same question in plain language: he picks this tool, does the calculation and files the result in your project.

My recipe is 40 IBU for a gravity of 1.050, is that balanced?

The ratio is 0.80: your beer will be clearly bitter, in the spirit of a well-hopped pale ale. For a gentler blonde, aim for 25 to 30 IBU.

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