Sourdough Starter Feeding Calculator
Work out how much to feed sourdough starter for a chosen amount or your next bake. Get grams of starter, flour and water, plus discard.
Result
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Result
— starter to keep
- Flour to add
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- Water to add
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- Resulting total
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- Discard
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Keep a little extra beyond the recipe amount so some remains to carry forward. Discard is usable in recipes rather than waste.
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Track it in Sourdough Tracker.
Track sourdough recipes, feeding notes and bake schedules in one place on your device.
How much to feed sourdough starter
To answer how much to feed sourdough starter, choose the amount you want to keep, or work backward from the amount your next bake needs. The calculator uses starter : flour : water by weight and shows the discard separately.
A larger feeding ratio means less starter relative to food, so it takes longer to peak. A 1:1:1 feed is faster, while 1:5:5 and 1:10:10 suit a longer wait or a warm kitchen. At 100% hydration, flour and water have equal weights; lower hydration makes a stiffer starter that ferments more slowly with a milder, less acetic flavour.
When working backward, always keep a little extra beyond the recipe amount so some remains to carry forward. Discard is usable in recipes rather than waste. For nearby calculations, see the [starter feeding ratio calculator](/tools/starter-feeding-ratio-calculator), [sourdough hydration calculator](/tools/sourdough-hydration-calculator) and [bulk fermentation calculator](/tools/bulk-fermentation-calculator).
Flour = starter kept × F; water = flour × hydration ÷ 100; total = starter kept + flour + water; backwards: starter kept = bake need ÷ (1 + F + W) Sourdough starter feeding FAQ
What does a 1:5:5 feeding ratio mean?
It means one part starter, five parts flour and five parts water by weight. Keeping 50 g starter therefore calls for 250 g flour and 250 g water.
Why does a larger ratio take longer to peak?
A larger ratio contains less starter relative to the amount of fresh food, so fermentation takes longer to peak.
How much starter should I keep for a recipe?
Work backward from the starter the recipe needs, then keep a little extra so some remains to carry forward after baking.
What is 100% hydration?
It means the starter has equal weights of flour and water. A lower target, such as 50–60%, produces a stiffer starter.
Is sourdough discard waste?
No. Discard is usable in recipes rather than waste; the calculator simply reports how much is left after keeping the amount needed for feeding.