When writing a recipe (formula), Baker’s Percentage or Baker’s Math is a way to express the ratio of ingredients to one another by weight. Each ingredient in a formula is expressed as a percentage of the largest ingredient, usually the flour weight, always expressed as 100%. Bakers often talk about the percent hydration of a dough; that is the amount of water (liquid) in a formula in ratio to the amount of flour.
Check how to calculate with this great tutorial.
