Enter how much starter you have and the ratio you want — get exact flour and water weights, your discard amount, and an honest peak-time window.
Updated · How we source our numbers
A 1:5:5 feed is 1 part starter to 5 parts flour and 5 parts water by weight. For example: 50 g starter, 250 g flour, 250 g water. A 1:1:1 feed peaks in about 4–6 hours; 1:5:5 takes about 8–14 hours at room temperature.
A feeding ratio is written starter : flour : water, always by weight. The first number is your mature starter (the “seed”); the next two are how much fresh flour and water you add relative to it.
So a 1:5:5 feeding of 50 g of starter adds 250 g flour and 250 g water, giving 550 g total. When the flour and water parts are equal, your starter stays at 100% hydration.
If your recipe calls for a specific amount of levain, switch to “I need this much levain” mode. The tool divides your target by (1 + flour-parts + water-parts) to tell you how little seed starter you actually need to begin with — so you generate less discard.
Lower ratios feed the starter less, so it peaks faster and tastes tangier. Higher ratios stretch the time to peak, which is what you want for an overnight build or a cooler kitchen. These windows are for roughly 21–24 °C (70–75 °F). We checked them against King Arthur Baking’s feeding-ratio trial. At a warmer 78 °F, its 1:1:1 feed peaked in about 4 hours, 1:2:2 in about 8 and 1:4:4 in about 12:
| Ratio | Peak window | Best for |
|---|---|---|
| 1:1:1 | ~4–6 h | Same-day bake; tangier |
| 1:2:2 | ~6–10 h | Daily; evening feed → morning bake |
| 1:3:3 | ~6–10 h | Balanced rise |
| 1:4:4 | ~8–12 h | Overnight boost |
| 1:5:5 | ~8–14 h | Overnight levain; milder |
| 1:10:10 | ~16–24 h | Weekly / before the fridge |
Temperature shifts every one of these — warmer is faster, cooler is slower. That’s why this tool gives a window and a doneness cue rather than a single “ready at 7:42” time the way some calculators do. Your starter doesn’t read clocks.