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1:2:2 sourdough starter feeding calculator

A 1:2:2 feeding means 1 part starter, 2 parts flour and 2 parts water, all by weight. To keep 50 g of starter, add 100 g of flour and 100 g of water. The jar then holds 250 g.

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)

1:2:2 means 1 part starter, 2 parts flour and 2 parts water, by weight.

A steady middle path. Good for two feedings a day. 1:1:1 versus 1:5:5

Your feeding

Show amounts in grams, ounces or cups

Feed 50 g starter, 100 g flour and 100 g water.

Starter
50 g
Flour
100 g
Water
100 g
Total after feeding
250 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 1:2:2 by weight, 100% hydration.

Rough peak time

about 5.5 to 8 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%

The numbers

Flour and water to add for common starter amounts at 1:2:2
Starter you keepFlourWaterJar total
10 g20 g20 g50 g
20 g40 g40 g100 g
50 g100 g100 g250 g
100 g200 g200 g500 g
200 g400 g400 g1,000 g

Amounts use 100% hydration and white flour. Change hydration or the flour mix in the tool above.

When to use 1:2:2

Use 1:2:2 for a steady routine. It is a good middle path for a starter that lives on the counter and gets two feedings a day.

It also works when you need a bit more starter than you keep. Feeding 40 g of starter gives 200 g in the jar, enough for most loaves.

How long a 1:2:2 feeding takes to peak

At 75 °F, a 1:2:2 feeding usually peaks in 5.5 to 8 hours. In a cool 68 °F kitchen, expect 7 to 10 hours. In a warm 82 °F kitchen, expect 4 to 6 hours. These are guides for an active starter at 100% hydration fed with white flour.

The feeding dilutes the starter about five times, so the peak comes later than with 1:1:1 but earlier than with 1:5:5. That gives a gap of about half a day between feedings.

A common mistake

Some bakers switch ratios every day, then wonder why the starter is unpredictable. Pick one ratio for a week and note when the jar peaks. Change the ratio only if that time does not suit you.

Quick answers

How much flour and water do I add for 1:2:2 with 20 g of starter?

Add 40 g of flour and 40 g of water to 20 g of starter. The jar holds 100 g after the feeding.

Is 1:2:2 the right ratio for me?

It is right for a morning and evening routine. If your day has one long gap, use a larger ratio so the peak lands near your next feeding.

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