Question 1

What is an IBU calculator?

Accepted Answer

An IBU calculator computes the International Bitterness Units of your beer based on hop amount, alpha acid percentage, boil time and original gravity. Our calculator uses the proven Tinseth formula which accounts for hop utilization. IBU values range from ~5 (light lager) to over 100 (Double IPA).

Question 2

How do you calculate the alcohol content (ABV) of beer?

Accepted Answer

Alcohol by volume is calculated from the difference between original gravity (OG) and final gravity (FG). The most common formula is: ABV = (OG - FG) × 131.25. Measure the OG before fermentation and the FG after fermentation using a hydrometer or refractometer.

Question 3

How much priming sugar do you need for carbonation?

Accepted Answer

The amount of priming sugar depends on the desired CO₂ level (in g/L or volumes) and temperature. A typical ale needs about 5-7 g/L of table sugar per liter of beer. Our carbonation calculator computes the exact amount for table sugar, corn sugar or Speise.

Question 4

Why do refractometer readings need correction?

Accepted Answer

Refractometers measure the refractive index of the liquid. During fermentation, alcohol distorts the reading so the displayed Brix value is higher than the actual final gravity. Our refractometer calculator corrects this error and shows the true final gravity in Brix and Plato.

BU:GU Calculator