Everything is worked out in your browser and saved on this device for next time.
About the sourdough calculator
Tell the calculator how much dough you want — or how much flour — and your hydration, starter and salt percentages. It gives you the flour to add, the water to add, the starter and the salt in grams.
A sourdough starter is half flour and half water (at 100% hydration). Many simple calculators forget this, so the real dough comes out wetter than planned. This calculator counts the starter in: its flour is part of "all the flour", and its water is part of the hydration. So 75% hydration really means 75%.
It also tells you how to feed your starter the night before, so you have enough — with a little left over for the jar.
Features
- From the dough weight or the flour weight — for 1 loaf or many
- The starter counted in — its flour and water are part of the baker's percentages
- Any starter hydration — 100% is the default; a stiff starter at 50–60% works too
- Two ways to count the starter — as a share of all the flour, or only of the flour you add
- A feeding plan — 1 : 1 : 1, 1 : 2 : 2 or 1 : 5 : 5, with 10% extra
- A full table — every ingredient in grams and in baker's percent
- Saved on this device — your recipe is still there for the next bake
What are baker's percentages?
Every ingredient is a percent of the flour. The flour is always 100%. A dough with 75% hydration has 75 g of water for every 100 g of flour, and 2% salt means 2 g of salt per 100 g of flour.
For sourdough, the percentages count all the flour and all the water — also the flour and water inside the starter. With 20% starter at 100% hydration, the starter is 20% of all the flour in weight, and half of it is flour.
| Term | What it means |
|---|---|
| Hydration | All the water ÷ all the flour |
| Starter (or levain) % | Starter weight ÷ all the flour |
| Starter hydration | Water in the starter ÷ flour in the starter (100% = equal weights) |
| Salt % | Salt ÷ all the flour |
Worked example
The page opens with 1 loaf of 1,000 g, 75% hydration, 20% starter at 100% hydration and 2% salt.
- All the flour: 1,000 ÷ (1 + 0.75 + 0.02) = 565 g
- All the water: 565 × 75% = 424 g
- Starter: 565 × 20% = 113 g — that is 56.5 g of flour and 56.5 g of water
- Flour to add: 565 − 56.5 = 508 g
- Water to add: 424 − 56.5 = 367 g
- Salt: 565 × 2% = 11.3 g
Check: 508 + 367 + 113 + 11.3 = 999.3 g — 1,000 g before rounding.
The night before, feed the starter 1 : 1 : 1: 41.7 g of starter from the jar, 41.7 g of flour and 41.7 g of water. That makes about 125 g of ready starter — a little more than the 113 g you need.
Sourdough for every loaf size
At 75% hydration, 20% starter (100% hydration) and 2% salt:
| Dough | Flour to add | Water to add | Starter | Salt |
|---|---|---|---|---|
| 500 g | 254 g | 184 g | 56.5 g | 5.6 g |
| 750 g | 381 g | 275 g | 84.7 g | 8.5 g |
| 900 g | 458 g | 331 g | 102 g | 10.2 g |
| 1,000 g | 508 g | 367 g | 113 g | 11.3 g |
Which hydration should I use?
For a 1,000 g loaf with 20% starter and 2% salt:
| Hydration | Flour to add | Water to add | Starter | Good for |
|---|---|---|---|---|
| 65% | 539 g | 329 g | 120 g | your first loaves — easy to shape |
| 70% | 523 g | 349 g | 116 g | a soft, everyday loaf |
| 75% | 508 g | 367 g | 113 g | a more open crumb |
| 80% | 495 g | 385 g | 110 g | an open crumb, but a sticky dough |
Whole wheat and rye flour drink more water, so they can take a higher hydration than white bread flour.
Frequently asked questions
Does the starter count in the hydration?
Yes, here it does. A 100% starter is half water, so its water is part of the dough. The calculator takes it away from the water you add, so the hydration you type is the real hydration of the dough.
How much starter should I use?
Most recipes use 15–25% of the flour. More starter makes the dough rise faster; less starter gives you more time, which helps on a warm day.
What does "Starter % is a share of" mean?
Bakers count the starter in two ways. The standard way (this calculator's default) takes the starter as a percent of all the flour. Many home recipes take it as a percent of only the flour you add — "100 g of starter for 500 g of flour = 20%". Open More options to switch. With 1,000 g of dough and 20%, the second way gives 103 g of starter instead of 113 g.
What is a 1 : 1 : 1 feeding?
One part starter from the jar, one part flour and one part water, by weight. A 1 : 2 : 2 or 1 : 5 : 5 feeding uses less starter, so it takes longer to peak — good when you feed at night and mix in the morning.
My starter is stiff (50% hydration). Can I use it?
Yes. Open More options and set Starter hydration to 50. The calculator then knows the starter holds less water and adds more water to the dough.
Related tools
- Pizza Dough Calculator — flour, water, salt and yeast for pizza
- Recipe Scaler — make a recipe bigger or smaller
- Cups to Grams Converter — change cups of flour into grams
- Baking Pan Converter — swap one pan size for another
- Oven Temperature Converter — °F, °C and gas mark
How to use it
- Choose From the dough weight or From the flour weight
- Type the Number of loaves and the Dough per loaf — or tap a Loaf size. Or type All the flour, with the starter's flour
- Set the Hydration, Starter and Salt percentages — or tap a Hydration button
- Open More options to change the Starter hydration, how the starter is counted, or how you Feed the starter
- Read the flour, water, starter and salt in the result, and the feeding plan in the table
- Press Copy to keep the list
