Sourdough Feeding Calculator

Plan sourdough starter feeds by ratio, room temperature, and feed time. Estimate peak window, refresh timing, and a practical bulk-fermentation handoff.

Last updated: 2026-03-16

Sourdough feeding calculator

Enter your values

Estimate how much flour and water to add, when your starter should peak, and when bulk fermentation will likely be ready.

Peak Window

Enter your starter size, feed ratio, room temperature, and feed time to estimate the next feeding cycle.

Calculation History (0)

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Example calculations

Tap an example to prefill the calculator with sample values.

Morning bake prep

30 g starter, 1:2:2 feed, 72°F kitchen

A common morning refresh that peaks in time for an afternoon dough mix.

Result: Add 60 g water + 60 g flour and expect a mid-afternoon peak

Cool-house slow build

25 g starter, 1:3:3 feed, 66°F room

A cooler room and bigger feed stretch the fermentation window out.

Result: Larger feed with a late-afternoon or early-evening peak

Warm weather maintenance

40 g starter, 1:1:1 feed, 78°F room

A warm kitchen can make small feeds race to peak, so timing matters.

Result: Shorter peak window and earlier next refresh time

What the timing estimate is optimizing

The calculator combines inoculation size and room temperature to estimate when a feed is likely to peak. That helps you choose whether a smaller, faster feed or a larger, slower feed better fits your baking day.

Use the output as a planning lane, not a stopwatch. Your starter’s strength, flour mix, and actual dough temperature still matter once you start mixing bread.

Sourdough feeding FAQs

A quick guide to starter ratios, peak timing, and planning around the bake.

What does a 1:2:2 feed mean?

It means one part starter, two parts water, and two parts flour by weight. If you keep 30 grams of starter, a 1:2:2 feed adds 60 grams of water and 60 grams of flour.

Why does room temperature matter so much?

Starter activity speeds up in warmer kitchens and slows down in cooler ones. The calculator uses temperature as a timing nudge so the peak estimate reflects real-world kitchen conditions better than the ratio alone.

Is the bulk-fermentation timing exact?

No. It is an estimate meant to help planning. Flour choice, starter strength, dough temperature, hydration, and salt timing can all shift bulk fermentation in either direction.

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Disclaimer

This calculator provides general estimates for hobby projects. Results may vary based on specific conditions, materials, and techniques.

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