Enter your flour weight, hydration percentage, starter percentage, and salt percentage to get a complete sourdough bread recipe using baker's math. Your Sourdough Calculator returns exact gram weights for flour, water, starter, and salt — plus your dough's total hydration level — so you can scale any loaf without mental math.
Total Dough Weight
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Flour
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Water
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Starter
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Salt
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True Dough Hydration
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Baker's math expresses every ingredient as a percentage of the total flour weight, which is always 100%. So if you have 500g of flour and 375g of water, your hydration is 75%. This system makes it easy to scale recipes up or down and compare different formulas regardless of batch size.
Hydration refers to the ratio of water to flour in your dough, expressed as a percentage. A 75% hydration dough uses 75g of water for every 100g of flour. Higher hydration doughs produce a more open, airy crumb but are stickier and harder to handle — 65–75% is a good starting point for beginners.
Most recipes use 10–25% starter relative to flour weight. Using more starter speeds up fermentation, while less starter slows it down and develops more complex flavour. In a typical home kitchen around 75°F (24°C), 20% starter will be ready to bake in roughly 4–6 hours after bulk fermentation.
The most common starter hydration is 100%, meaning equal parts flour and water by weight. This calculator defaults to 100% hydration but also supports 50% (stiff), 75%, and 125% (liquid) starters. Your starter's hydration affects how much water and flour it contributes to your dough, which is accounted for in the true hydration calculation.
Your starter is made of flour and water, so it contributes to both the dough's total flour and water. A 100g portion of 100% hydration starter contains 50g flour and 50g water. This calculator factors that in when computing 'True Dough Hydration', giving you an accurate picture of the actual water-to-flour ratio across all ingredients.
The standard amount is 2% of the total flour weight — so 10g of salt for every 500g of flour. Salt slows fermentation slightly, strengthens gluten structure, and is essential for flavour. You can adjust between 1.8% and 2.2% to taste, but going below 1.5% risks a flat, under-fermented loaf.
Yes — simply set the 'Number of Loaves' field to how many loaves you want to bake, and all ingredient weights will be scaled proportionally. The percentages stay the same; only the gram amounts change.
A beginner-friendly formula is 75% hydration, 20% starter, and 2% salt. This gives a manageable dough that's not too sticky, ferments at a predictable rate in a warm kitchen, and produces a delicious loaf with a decent crumb structure. As you gain confidence, try increasing hydration to 80% or beyond.