About this tool
Baker's Percentage / Hydration Calculator is a free, in-browser tool for bread and pastry formulas written in baker's math, where every ingredient is expressed as a percentage of the flour weight (flour is always 100%). It works both ways: turn percentages into gram weights, or turn weights into percentages and read off the hydration. All figures are computed on your device.
In Percent → Weights mode you enter the flour weight in grams and each ingredient's percentage; every weight is flour × percentage ÷ 100. In Weights → Percent mode you enter each weight and it returns percentage = weight ÷ flour × 100. Hydration — the headline number for dough texture — is the water weight divided by the flour weight, as a percentage.
Baker's percentages make a formula scale to any batch size and let you compare recipes at a glance: a 75% hydration dough is wetter and more open than a 60% one. Sugar, butter and oil are optional and only appear when their value is above zero.