PRAL Acid Load Calculator

About this calculator

PRAL (potential renal acid load) is a formula developed by Remer and Manz (1995) that estimates whether a food or diet will produce a net acid or net alkaline load for the kidneys to excrete: PRAL (mEq/day) = 0.49×protein(g) + 0.037×phosphorus(mg) − 0.021×potassium(mg) − 0.026×magnesium(mg) − 0.013×calcium(mg). A positive value means the food is acid-forming (mostly meat, fish, cheese, and grains), while a negative value means it's alkaline-forming (mostly fruits and vegetables).

Dietitians, nephrology patients on renal diets, and followers of the alkaline diet use PRAL to select foods that reduce dietary acid load, since a chronically high acid load has been linked to bone mineral loss and is a factor clinicians weigh in chronic kidney disease management.