Baker's Percentage Calculator
Scale bread formulas from flour weight or total dough — with the starter folded in correctly.
Scale bread formulas from flour weight or total dough — with the starter folded in correctly.
20% starter at 100% hydration brings half its weight as water and half as flour — the calculator splits it for you.
Enter a flour or dough weight to scale the formula — the defaults are a 70% hydration lean dough.
Frequently asked questions
What is baker's percentage?
Every ingredient is expressed as a percentage of the flour weight, and flour is always 100%. A dough of 1000 g flour, 700 g water, 20 g salt and 10 g yeast is '70% hydration, 2% salt, 1% yeast'. Percentages make formulas scalable and comparable — the same numbers mean the same dough whether you bake 500 g or 5 kg.
Why is flour always 100%?
Because flour is the reference everything else scales against — including the flour hiding in your starter. A 1000 g formula with 20% starter at 100% hydration really contains 1100 g of flour (1000 + 100 from the starter) and 700 g of total water (600 added + 100 carried in). Ignore that split and your '70%' dough quietly bakes tighter than the formula promises.
Does starter count toward hydration?
Yes — the water in starter is dough water. Starter at 100% hydration is half water by weight, so 200 g of it contributes 100 g of water and 100 g of flour. That is exactly why this calculator lists 'water to add' (600 g in the standard example) separately from total water (700 g): the jug you actually pour needs only the added part.
65% vs 80% hydration?
Per 1000 g of flour, 65% is 650 g water — a firm, easy-to-shape dough for sandwich loaves and bagels. 80% is 800 g water — a slack, open-crumb dough for ciabatta and rustic loaves that wants wet hands and a folding technique. Same flour, same salt; the hydration number alone moves the dough from machine-tame to bitingly wet. Most beginner-friendly artisan breads live between the two.
How do I scale a recipe for two loaves?
Scale the flour, not the finished dough: if one loaf uses 500 g flour at 70%, two loaves are 1000 g flour → 700 g water, 20 g salt, 10 g yeast. Or work backwards: you weighed 1830 g of finished dough from the standard example formula and want it again — enter 1830 in dough mode and the calculator hands back the 1000 g flour base.
How the formula is computed
One substance splits three ways: the starter is flour + water at its own hydration, and it must be accounted inside both the flour and water totals.
1. Starter mass = F × starter%. 2. Split it at the starter's hydration: at 100% it halves (100 g flour + 100 g water from 200 g); at 60% it splits 62.5/37.5. 3. Water to add = F × hydration − starter water. 4. Total flour = F + starter flour. 5. Total dough = flour + added water + salt + yeast + starter.
Worked example — the 1000 g flour standard:
Starter: 20% of 1000 = 200 g, split 100 g flour + 100 g water at 100% hydration. Water: 700 total − 100 in the starter = 600 g to add. Salt 20 g, yeast 10 g. Total dough: 1000 + 600 + 20 + 10 + 200 = 1830 g. Enter 1830 in dough mode and the calculator hands back 1000 — the round trip closes.
Why most calculators get the starter wrong
The common bug: listing 'water = 70%' at full value while also listing the starter as a separate line. That double-counts 100 g of water — the dough comes out 100 g heavier than the percentages promise, or the baker chases a drier dough that was never dry.
The fix is the half-split: starter at 100% hydration is exactly half flour, half water. Fold those halves into the flour and water totals, list only the water you add, and the dough weight is the honest sum — 1830 g, not 1930 g.
Formulas assume salt and yeast percentages of the formula flour. Commercial preferment staging may differ — adjust if your process builds the levain separately.
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