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Starter Feeding Calculator
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Sourdough starter feeding calculator

Pick a ratio. Get the grams of starter, flour and water to feed, and a rough time to peak.

What do you know?

The starter left in the jar after you discard.

Weigh the jar, then subtract the empty jar. We use it to tell you how much to discard.

Feeding ratio (starter : flour : water)

1:1:1 means 1 part starter, 1 part flour and 1 part water, by weight.

Peaks fast, so you feed often. Tangier starter. 1:1:1 versus 1:5:5

Your feeding

Show amounts in grams, ounces or cups

Feed 50 g starter, 50 g flour and 50 g water.

Starter
50 g
Flour
50 g
Water
50 g
Total after feeding
150 g

Discard

Type the weight of the starter in your jar to see how much to discard.

Keep 50 g of starter in the jar and discard the rest. Then add the flour and water. Ratio 1:1:1 by weight, 100% hydration.

Rough peak time

about 3.5 to 5 hours

At 75 °F. A guide only: your flour, starter and kitchen will change it. Watch the jar, not the clock.

Fine-tune

100% means equal flour and water. Used with the preset ratios.

Temperature unit

Used only for the peak time guide.

Clock times (optional)

Fill in one to see clock times for the peak. Fill in both to get a ratio that fits your night.

Flour mix (optional)

White flour (all-purpose or bread): 100%

What a sourdough starter feeding calculator does

A sourdough starter feeding calculator turns a feeding ratio into grams. You say how much starter you want to keep, or how much you need in total. You pick a ratio such as 1:5:5. The calculator tells you how much starter, flour and water to use. It also gives a rough guess of when the starter will peak in your kitchen.

How to use this calculator

  1. Choose Starter I keep if you know how much starter stays in the jar. Choose Total I need if a recipe asks for a set weight of fed starter.
  2. Type the amount in grams, or tap a quick amount.
  3. Pick a ratio. Use 1:1:1 for a fast feeding. Use 1:5:5 or 1:10:10 for a slower rise. Pick Custom for any other mix.
  4. Change the hydration if your starter is not at 100%. Enter your kitchen temperature to see the peak time guide.
  5. Weigh the amounts on a kitchen scale. Use Copy amounts to paste them into a note.

What the feeding ratio numbers mean

A ratio of 1:5:5 means 1 part starter, 5 parts flour and 5 parts water, all by weight. If you keep 50 g of starter, you add 250 g of flour and 250 g of water. The jar then holds 550 g. A bigger feeding spreads the yeast and bacteria thinner, so the starter takes longer to peak. That gives a slower rise and a milder flavor.

Common feeding ratios for 50 g of starter, with rough peak times at three kitchen temperatures
RatioAdd to 50 g starterPeak at 68 °FPeak at 75 °FPeak at 82 °F
1:1:150 g flour, 50 g water4.5 to 7 hours3.5 to 5 hours2.5 to 4 hours
1:2:2100 g flour, 100 g water7 to 10 hours5.5 to 8 hours4 to 6 hours
1:5:5250 g flour, 250 g water11 to 16 hours8 to 12 hours6 to 9 hours
1:10:10500 g flour, 500 g water14 to 20 hours10 to 16 hours8 to 12 hours

The times assume an active starter at 100% hydration fed with white flour. Treat them as a guide.

  • 1:1:1 is fast. Use it to wake a starter from the fridge or when you want to bake today.
  • 1:2:2 is a steady middle path for a starter you feed twice a day.
  • 1:5:5 suits one feeding a day on the counter.
  • 1:10:10 suits an overnight feeding, or a warm kitchen where a smaller feed would peak too early.

How much to feed 20 g, 50 g, 100 g or 200 g of starter

These amounts use a 1:5:5 feeding at 100% hydration. Keep the starter amount in the jar, then add the flour and water.

Flour and water to add to common starter amounts at 1:5:5
Starter you keepFlourWaterTotal
20 g100 g100 g220 g
50 g250 g250 g550 g
100 g500 g500 g1100 g
200 g1000 g1000 g2200 g

A worked example

A bread recipe asks for 110 g of ripe starter. You feed at 1:5:5 and want exactly that amount. Choose Total I need, enter 110 and pick 1:5:5. The calculator gives 10 g of starter, 50 g of flour and 50 g of water. Mix them in a clean jar and mark the level with a rubber band. In a 75 °F kitchen, expect the peak in 8 to 12 hours. If your jar holds more starter than 10 g, discard the extra first.

How temperature changes the timing

Yeast works faster when it is warm. As a rule of thumb, the wait gets about half as long for every 18 °F (10 °C) of extra warmth. The same 1:5:5 feeding takes 11 to 16 hours at 68 °F and 6 to 9 hours at 82 °F. Below 59 °F the starter slows a lot. Above 95 °F it can turn sour and weak.

If your kitchen is cold, try the oven with only the light on, or the top of the fridge. Do not rely on the clock alone. A ripe starter has a domed top, many bubbles and a level that has about doubled. Feed it at or just after the peak.

Hydration and flour mix

Most bakers keep starter at 100% hydration, which means equal weights of flour and water. A stiff starter at 60% to 80% uses less water. When you change the hydration here, the total weight of the feeding stays the same and the split between flour and water changes. The calculator assumes your starter already has that hydration.

Whole wheat and rye give the yeast more to eat. A starter fed with them often peaks sooner and may not rise as tall. Open Flour mix to split the flour weight, for example 80% white and 20% whole wheat.

How much to discard

Type the weight of the starter in your jar into Starter in my jar now. The Discard card then says how much to remove, and how much flour and water to add. If the jar holds less than the amount you want to keep, the card says how many grams are missing.

Feeding guides for specific cases

Tips for steady feeding

  • Weigh, do not scoop. Grams are the same every time. Cups are not.
  • Use the same jar. Mark the starting level with a band or tape so you can see the rise.
  • Feed at the same time each day. A steady schedule gives a steady starter.
  • Keep a starter in the fridge if you bake less than once a week. Feed it about weekly. Before baking, feed it once or twice at room temperature.

Frequently asked questions

How much should I feed my sourdough starter?

Feed by weight. Most bakers add equal parts flour and water, and use 1 to 10 times the weight of the starter they keep. A 1:1:1 feeding peaks fast. A 1:5:5 or 1:10:10 feeding peaks later and suits a once-a-day schedule. Pick the ratio that matches how often you can feed.

What does a 1:5:5 starter feeding mean?

It means 1 part starter, 5 parts flour and 5 parts water, all by weight. If you keep 20 g of starter, you add 100 g of flour and 100 g of water. The jar then holds 220 g.

How often should I feed my starter?

On the counter, feed once or twice a day. A starter in the fridge needs a feeding about once a week. Before you bake, take it out and feed it once or twice at room temperature until it rises well.

How much starter do I discard before feeding?

Keep only the amount you enter under Starter I keep (grams) and discard the rest. Type the weight of your jar into Starter in my jar now, and the Discard card tells you the exact amount. You can bake with the discard, for example in pancakes or crackers. A small amount of starter in a large feed gives the longest wait before the peak.

Can I measure starter, flour and water in cups?

You can, and the calculator has a cups view. It is a guess, because a cup of flour can weigh anywhere from 100 to 150 g depending on how you scoop it. A kitchen scale gives the same result every time and costs very little.

How does hydration change a feeding?

Hydration is the weight of water as a percent of the weight of flour. At 100%, you add equal flour and water. At 80%, you add less water and more flour for the same total feed. The starter feels thicker and often ferments a little slower.

How long until my starter peaks after feeding?

It depends on the feeding ratio and the temperature. In a 75 °F kitchen, a 1:1:1 feeding peaks in about 3.5 to 5 hours and a 1:5:5 feeding in about 8 to 12 hours. Look for a domed top, many bubbles and a level that has doubled. The estimate on this page is a guide only.

How much do I feed 100 g of starter?

At 1:5:5, keep 100 g of starter and add 500 g of flour and 500 g of water. The jar then holds 1100 g. For a smaller feeding, use 1:1:1 and add 100 g of each.

How do I wake a starter from the fridge?

Take it out and let it warm up for an hour. Discard most of it, keep a small amount, and feed it at 1:2:2 or 1:5:5. Repeat once or twice a day until it doubles within 4 to 8 hours. Then it is ready to bake with.

My starter is runny or very thick. What should I change?

A runny starter often has too much water. Lower the hydration to 80% and feed it again. A very thick starter is stiff and slow. Raise the hydration to 100% and stir well. Change one thing at a time and watch the jar for a few feedings.

What if my starter does not peak or rise?

Check the kitchen first. Below 68 °F a starter is slow, so move the jar somewhere warmer. Then feed it more often with a smaller amount of old starter, for example 1:1:1 twice a day. Use unchlorinated water and a flour with some whole grain in it. Most weak starters recover in a few days.

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