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Powerful features designed for every sourdough baker
What Is Baker's Percentage?
Baker's percentage (also called baker's math) is the standard method professional bakers use to express ingredient ratios in bread recipes. Every ingredient is measured as a percentage of the total flour weight, which is always set to 100%. For example, in a recipe with 500 g flour and 375 g water, the hydration is 75% (375 ÷ 500 × 100).
This system makes it easy to scale recipes up or down, compare different formulas, and adjust hydration or starter ratios without recalculating every ingredient from scratch. Whether you're baking a single loaf or a hundred, the percentages stay the same — only the flour weight changes.
Our free sourdough ratio calculator handles all the math for you. Enter your desired dough weight and hydration percentage, and it instantly computes the exact amounts of flour, water, sourdough starter, and salt you need. It also factors in the water and flour already present in your starter, so your final hydration is always accurate.
Understanding baker's percentage is the single most important skill for consistent sourdough baking. Once you learn to think in ratios rather than fixed weights, you can adapt any recipe to your schedule, your oven, and your taste.
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Loved by Bakers
Finally, a calculator that is intuitive and actually helpful. No more spreadsheets!
Sarah M.
Home Baker
The fermentation timing based on temperature has completely changed my results.
James T.
Sourdough Enthusiast
As a professional, I appreciate the accuracy and ability to save multiple recipes.
Maria G.
Artisan Bakery
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