Analyze true baker's percentages including starter flour and starter water. Useful for converting recipes, scaling loaves, and fixing dough that is too stiff or too wet.
This tool is part of these guided projects. Each project provides step-by-step instructions with checklists and all the tools you need in one place.
Tools you might need next
Calculate coffee, water, bloom, pour stages, grind, and brew time for pour-over, AeroPress, French press, and cold brew coffee recipes.
Calculate beer, cider, or mead ABV from original gravity and final gravity. Includes attenuation, packaged servings, standard drinks, and rough calories.
Convert knitting pattern gauge to your swatch gauge. Calculate cast-on stitches, row counts, stitch multiples, and pattern size adjustments.
Starter flour and starter water are derived from starter weight and starter hydration, then added to the main flour and water totals.
starter flour = starter / (1 + starter hydration / 100)Hydration is total water divided by total flour. This is more accurate than comparing only the added flour and added water.
The Sourdough Hydration Calculator scales ingredient quantities linearly by serving count or batch size. Non-linear items (yeast, salt, leavening) may use sub-linear scaling factors.
Scaled Amount = Base × (New Servings ÷ Original Servings)Updated: July 2026
Enter the current formula and target hydration to see how much water to add or remove.
Use dough weight and loaf count to portion dough before shaping.
A host doubles or triples a favorite recipe using the Sourdough Hydration Calculator so ingredient weights stay balanced for a larger batch.
A 100% hydration starter contributes equal flour and water, which changes the real dough hydration.
Hold back a small amount of water when using whole grain flour, seeds, or unfamiliar flour strength.
Analyze a sourdough formula the way bakers do: include the flour and water inside the starter, then calculate hydration, salt percentage, inoculation, and dough weight.