The IBUcalculator app is used to compute the expected bitterness of homebrew based on the type, amount, and duration of hopping.
Although IBU offers standardization of brewing techniques, bitterness is a perceptual quality that varies among individuals. Consequently, most homebrewers prefer one method of IBU calculation over another because it tends to match their own subjective experience. The IBUcalculator is derived from the popular formulations of Glenn Tinseth.