Calculator
Baker’s percentage calculator
Flour is 100%. Water, salt, fat, sugar, and yeast are percentages of that flour. If you use a starter, its flour and water are already part of those totals. The “weigh these” list is what you add at the mixer.
Quick answer. 1000 g of flour at 70% hydration and 20% inoculation of a 100% hydration starter means you add 900 g flour, 600 g water, 20 g salt, and 200 g starter. True hydration stays 70%.
Weights
1,720 g dough · true hydration 70%
| Ingredient | Weight |
|---|---|
| Starter | 200 g |
| Flour | 900 g |
| Water | 600 g |
| Salt | 20 g |
| Part | Weight |
|---|---|
| Flour | 100 g |
| Water | 100 g |
| Starter total | 200 g |
Inoculation 20% of flour weight. Prefermented flour 10%. That flour and water are already inside the totals, so they are not added again.
| Ingredient | Baker’s % | Weight |
|---|---|---|
| Flour | 100% | 1,000 g |
| Water | 70% | 700 g |
| Salt | 2% | 20 g |
True hydration is total water divided by total flour, including what is already in the starter.
True hydration
Hydration here is all the water divided by all the flour. A 200 g starter at 100% hydration already contains 100 g flour and 100 g water. On a 1000 g flour, 70% hydration dough, you still need 700 g of water in total, so you pour 600 g and add 900 g of new flour. The dough is 70% hydration either way. The hydration guide and the baker’s percentage guide walk through the same arithmetic.
Inoculation is starter weight relative to total flour. Prefermented flour is only the flour inside the starter. At 100% starter hydration, prefermented flour is half the inoculation.
Questions
- What is baker’s percentage?
- Flour is 100%. Every other ingredient is a percent of the flour weight, not of the finished dough. Two percent salt on 1000 g of flour is 20 g of salt. On 800 g of flour it is 16 g. You do not recalculate the salt against the water.
- How do I count sourdough starter in hydration?
- Hydration is all the water divided by all the flour, including the flour and water already in the starter. A 200 g starter at 100% hydration holds 100 g flour and 100 g water. On 1000 g total flour at 70% water you still need 700 g of water, so you add 600 g of water and 900 g of new flour.
- What does 20% sourdough inoculation mean?
- Inoculation here is starter weight divided by total flour. Twenty percent on 1000 g of flour is 200 g of starter, at whatever hydration the starter is. Prefermented flour is only the flour inside the starter. At 100% starter hydration, prefermented flour is half the inoculation.
- Can I start from finished dough weight instead of flour?
- Yes. Choose finished dough weight and enter the weight you want. The calculator solves for the flour, then for water, salt, and the rest. The pizza dough calculator does the same thing for a set of balls.
- Does oil or butter count as hydration?
- No. Hydration is water only. Oil, butter, and sugar are their own percentages of the flour. A spoonful is not a percentage; weigh them.
Last reviewed 1 November 2026.
Sources
No outside survey is cited for a “correct” hydration. The 70% water, 2% salt, and 20% inoculation in the default are this page’s example, so the quick answer has numbers to show.
- The identity used here: flour weight is 100%, and hydration is all water divided by all flour, including a starter. The gram weights are that arithmetic, covered by this project’s tests.