A free sourdough bread calculator that uses baker's math to design and scale recipes — no more mental math in the kitchen.
This sourdough bread calculator helps you design and scale recipes by adjusting hydration, starter percentage, and dough weight. Whether you're baking at home or preparing for orders, this dough calculator ensures consistent fermentation and predictable results.
Our sourdough hydration calculator is built for:
Hydration is the weight of water as a percentage of the weight of flour. A 70% hydration dough has 700g of water for every 1000g of flour. Lower hydration (60–65%) gives a tighter, easier-to-handle crumb; higher hydration (75–85%) gives a more open, airy crumb but stickier dough.
Starter (or levain) is usually 10–20% of the flour weight. More starter ferments the dough faster; less starter ferments slower and develops more flavour. Warmer kitchens need less starter, cooler kitchens need more — this calculator factors your room temperature into the suggestion.
Baker's math expresses every ingredient as a percentage of the total flour, which is always 100%. A classic loaf might be 100% flour, 70% water, 20% starter, and 2% salt. Because everything is relative to flour, you can scale a recipe to any number of loaves without changing the ratios.
Yes — the calculator is completely free to use, with no account required. Create a free account only if you want to save your recipes.
Yes. By tracking hydration, starter percentage and room temperature together, it estimates fermentation and proofing times, so it doubles as a bulk fermentation calculator.
Absolutely — set the loaf count and the calculator scales every ingredient using baker's percentages, keeping your ratios identical no matter the batch size.