Calculator
Sourdough pizza dough, starter counted
The starter is the leavening. Its percent is starter weight divided by total flour, and its hydration splits that starter into flour and water already in the dough. You weigh only the flour and water that are left. Commercial yeast is not added.
Quick answer. 4 balls at 225 g, 65% hydration, 2% salt, and 20% of a 100% starter: add 485 g flour, 296 g water, 10.8 g salt, and 108 g starter. True hydration stays 65%. The 65% hydration, and the oil and sugar at 0%, are editable estimates. The 20% starter and 2% salt are from a cited bread timetable, not from King Arthur’s pizza grams.
Weigh
108 g starter · true hydration 65%
| Flour to add | 485 g |
|---|---|
| Water to add | 296 g |
| Salt | 10.8 g |
| Starter | 108 g |
The starter already holds 54 g flour and 54 g water. Total flour 539 g. Total water 350 g. Prefermented flour is 10% of the flour, from the starter percent and starter hydration. No commercial yeast.
Starter percent from a cited timetable
At 74°F (23°C), in a dough of 90% King Arthur bread flour, 10% whole wheat, and 2% salt, with starter fed 1:2:2: 20% starter reached a 75% rise in 8.5 hours and a 100% rise in 9.5 hours. At 10% starter the timetable lists 12.5 hours. The dough in that sentence is bread, not pizza. This calculator does not turn hours and temperature into a starter percent.
| Starter | What the timetable lists |
|---|---|
| 20% | 75% rise in 8.5 hours. 100% rise in 9.5 hours. |
| 10% | 12.5 hours. |
For a typical sourdough bread recipe, the author lets bulk fermentation play out at room temperature over 3 to 5 hours, and says the period is dictated by the bread, the desired dough temperature, and how warm the dough is kept. That note is about bread bulk fermentation. It is not a starter percentage.
King Arthur’s printed pizza grams
Sourdough Pizza Crust, Bryan Ford, updated 5 February 2025, yields 4 pizzas of 10 to 12 inches, divided into pieces of 225–235 g. The ripe starter’s hydration is not printed, so the grams below are not turned into one hydration.
| Ripe starter in the levain | 50 g |
|---|---|
| Levain flour | 100 g |
| Levain water | 100 g |
| Levain used in the dough | 200 g |
| Dough water | 275 g |
| Table salt | 15 g |
| 00 pizza flour | 475 g |
| Rye | 13 g |
| Whole wheat | 13 g |
| Flour added to the dough | 501 g |
The levain is built from 50 g starter, 100 g flour, and 100 g water. The dough uses 200 g of it. The recipe says the rest is leftover and does not print a leftover weight. Semolina is optional, for shaping, and is not in the dough.
Levain: 3–4 hours at 72–75°F, or refrigerate up to 12 hours and then rest a couple of hours at room temperature. Bulk: about 4 hours, until nearly doubled. Then 24–48 hours in the refrigerator, and 2 hours at room temperature before baking. The oven in that recipe is 500°F for 10–15 minutes.
Questions
- Does the starter’s water count toward hydration?
- Yes. Starter percent is starter weight divided by total flour. The starter is then split by its hydration into flour and water, and those amounts are subtracted from what you weigh out. True hydration stays total water divided by total flour.
- Where does the 20% starter suggestion come from?
- The Sourdough Journey bulk-fermentation timetable, at 74°F (23°C), in a bread dough of 90% King Arthur bread flour, 10% whole wheat, and 2% salt, with starter fed 1:2:2. At 20% starter that dough reached a 75% rise in 8.5 hours and a 100% rise in 9.5 hours. At 10% starter the timetable lists 12.5 hours. That is a bread timetable, not a pizza rule.
- Why isn’t the King Arthur pizza recipe one hydration percent?
- The recipe prints 50 g of ripe starter, 100 g flour and 100 g water in the levain, and 200 g of that levain in the dough, plus 275 g water and 501 g of mixed flour. It does not print the ripe starter’s hydration, so those grams are not collapsed into one hydration or one inoculation percent.
- Can hours and temperature be turned into a starter percent?
- Not with this site’s commercial-yeast model. That model says it is not valid for sourdough. The page shows only the cited Journey percents and the King Arthur schedule with its printed grams.
- Is the 2% salt King Arthur’s pizza salt?
- No. Two percent is the salt in the Sourdough Journey bread timetable. King Arthur’s pizza recipe prints 15 g of table salt beside its own flour weights, and this page does not convert that into the default.
- What is the 65% hydration?
- An editable estimate. It is not taken from the Journey timetable and it is not calculated from the King Arthur pizza grams. Change it to the hydration you want. Oil and sugar start at 0% for the same reason: they are not in that bread timetable.
Last reviewed 1 November 2026.
Sources
Starter suggestions are the Journey bread timetable and the King Arthur pizza schedule as printed. The 65% hydration, 0% oil, and 0% sugar in the form are estimates you can edit. The commercial-yeast model is not used here.