Sourdough Calculator

Calculate flour, water, starter, and salt for your sourdough using baker's percentages.

By Konstantin Iakovlev · Updated April 2026 · Source: USDA

g
%
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Flour

508g

Water

381g

Starter

102g

Recipe (Baker's Percentages)

Flour (100%)508 g
Water (75%)381 g
Starter (20%)102 g
Salt (2%)10.2 g
Total Dough Weight1,000 g

Baking Timeline

Feed Starter8-12 hours before
Autolyse (mix flour + water)30-60 min
Add starter + salt, mix5-10 min
Bulk Fermentation (stretch & fold)4-6 hours
Pre-shape & rest20-30 min
Final shape5-10 min
Cold proof (refrigerator)8-16 hours
Bake (covered)20 min at 500°F
Bake (uncovered)20-25 min at 450°F
Cool1 hour minimum

Use the Sourdough Calculator above to calculate your results. Enter your values and see instant results — all calculations run in your browser.

Disclaimer: This calculator is for informational purposes only and does not constitute tax, financial, or legal advice. Results are estimates based on the information you provide and current rates. Always consult a qualified tax professional or financial advisor for advice specific to your situation.

How It Works

Every loaf starts from four weights: flour, water, starter, and salt. This tool pins down each one from baker's percentages so the dough behaves the same way every time you mix it. As home bakers in 2026 lean harder into repeatable results, working from precise grams rather than guesswork is what turns a good bake into a reliable one.

Baker's percentages anchor everything to the flour, which always counts as 100%. Water, starter, and salt are then expressed as a share of that flour weight. A typical recipe might run 70% hydration, 20% starter that is itself at 100% hydration, and 2% salt, with all three scaling off whatever flour weight you set as your starting point.

Weigh on a digital scale rather than measuring by cup, because volume readings drift badly in sourdough and small errors compound. The most overlooked detail is the flour and water already living inside your starter, which both count toward total hydration, so fold that contribution into the math. Where a starter runs at a different hydration, its percentage needs adjusting to match.

Example: Baking a 750g Flour Loaf

  1. 1 Input your desired total flour weight (e.g., 750 grams) and your preferred baker's percentages for water (e.g., 72%), starter (e.g., 22%), and salt (e.g., 1.8%).
  2. 2 The calculator processes these inputs: Water = 750g * 0.72 = 540g; Starter = 750g * 0.22 = 165g; Salt = 750g * 0.018 = 13.5g.
  3. 3 Your recipe requires: 750g bread flour, 540g water, 165g active sourdough starter, and 13.5g salt. This yields a dough with a total weight of 1468.5g.
  4. 4 This precise breakdown ensures optimal dough consistency and flavor development for your sourdough. You can now confidently mix your ingredients, knowing the ratios are perfectly balanced for a successful bake in 2026.

Source: USDA · Last updated: April 2026

Frequently Asked Questions

What is the right hydration for sourdough bread?
Beginner-friendly sourdough uses 65-70% hydration (650-700g water per 1000g flour). Higher hydration (75-85%) creates a more open crumb with bigger holes but is harder to handle.
How much sourdough starter should I use?
Most recipes use 15-25% starter relative to flour weight. For 500g of flour, that is 75-125g of active starter. More starter means a faster rise and more sour flavor.
What is baker percentage in sourdough?
Baker percentage expresses each ingredient as a percentage of the total flour weight. Flour is always 100%. A typical sourdough is 100% flour, 70% water, 20% starter, and 2% salt.