Sourdough Starter Feeding Calculator
Pick a feeding ratio, tell it how much starter you're keeping, and get exact flour and water amounts — or work backwards from how much ripe starter your recipe needs.
Common ratios:
Need a specific amount for a recipe?
How feeding ratios work
A ratio like 1:5:5 is starter : flour : water by weight. Keeping 20 g of starter at 1:5:5 means feeding it 100 g flour and 100 g water — 220 g total. Equal flour and water keeps your starter at 100% hydration; our hydration calculator handles what that means for your dough.
Which ratio should you use?
| 1:1:1 | The classic maintenance feed. Peaks fast — roughly 4–6 hours at room temperature — so it suits same-day baking. |
|---|---|
| 1:2:2 | A little more food, a little more time: peaks in about 6–8 hours. A good default if 1:1:1 keeps peaking before you're ready. |
| 1:5:5 | Peaks in roughly 8–12 hours — feed at night, bake in the morning. Also dilutes acidity, giving a milder flavor. |
| 1:10:10 | The long game: 12+ hours to peak. Useful in hot kitchens where small feeds exhaust themselves too quickly. |
Times shift with temperature — warm kitchens speed everything up, cold ones slow it down. Watch for the peak (domed top, bubbly, roughly doubled) rather than the clock.
Don't feed your whole jar
The calculator asks how much starter you're keeping because the standard practice is to discard most of the jar and feed a small remainder. Feeding your entire 200 g starter at 1:5:5 would produce over 2 kg of starter by tomorrow. Keep 20–50 g, feed that, and use the discard for crackers or pancakes.