Sourdough Calculator

Every loaf starts from four weights: flour, water, starter, and salt. This tool pins down each one from baker's percentages so the dough behaves the same way every time you mix it. Working from precise grams rather than guesswork is what turns a good bake into a reliable one.

Baker's percentages anchor everything to the flour, which always counts as 100%. Water, starter, and salt are then expressed as a share of that flour weight. A typical recipe might run 70% hydration, 20% starter and 2% salt. You enter the total dough weight you want, and the calculator works backward: flour = dough weight ÷ (1 + hydration + starter + salt), and each other ingredient is that flour weight times its percentage.

Weigh on a digital scale rather than measuring by cup, because volume readings drift badly in sourdough and small errors compound. The most overlooked detail is the flour and water already living inside your starter. The calculator treats the starter as a separate ingredient, so the hydration you enter is water to flour only: with 20% of a starter kept at 100% hydration, a 75% dough actually lands at about 77% once the starter's flour and water are counted. For a true 75%, set the hydration to 72.5%.