Sourdough Bread Calculator — Perfect Ratios Every Time
Flour
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Water
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Starter
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Salt
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Total Dough Weight
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Baker's Percentages for Sourdough Bread
Sourdough baking relies on baker's percentages, a system where every ingredient is expressed as a percentage of the total flour weight. This calculator scales sourdough recipes based on your desired dough weight, starter percentage, hydration level, and salt percentage. It accounts for the flour and water already present in the sourdough starter, ensuring your final dough hydration is accurate rather than just the added water.
The key calculation adjusts for the starter composition. A typical sourdough starter at 100% hydration is equal parts flour and water by weight. When you add 200g of starter to a recipe, you are actually adding 100g of flour and 100g of water. The calculator subtracts these amounts from the total flour and water to give you the correct quantities to mix. For a 75% hydration dough with 1000g total flour weight, you need 750g total water. If your starter contributes 100g of water, you only add 650g of additional water.
Hydration level dramatically affects the texture and handling of sourdough bread. Lower hydration doughs (60-65%) produce tight, chewy crumb structures suited for bagels and sandwich bread. Medium hydration (68-75%) creates the classic open crumb with moderate hole structure. High hydration doughs (78-85%) yield the large, irregular holes prized in artisan loaves but are significantly harder to shape and handle. This calculator lets you experiment with different hydration levels and starter ratios while maintaining consistent total dough weight.
Frequently Asked Questions
What hydration should I use?
65-70% makes a stiffer, easier-to-handle dough. 75% is a good all-round hydration. 80-85% creates an open, airy crumb but is harder to shape. Beginners should start at 70-75%.
How much starter should I use?
15-25% of flour weight is standard. Less starter (10-15%) gives a longer, more flavorful ferment. More starter (25-30%) speeds up fermentation but may reduce sourness and oven spring.
What is baker's percentage?
Baker's percentage expresses each ingredient as a percentage of total flour weight. Flour is always 100%. This makes scaling recipes easy. 75% hydration means 750g water per 1000g flour.