Scope and assumptions
Cooking percents are ratios of weights; baker's % uses flour as 100%. Illustrative.
A recipe that says 70% hydration is really speaking a ratio: 350 grams of water for every 500 of flour. Bakers set flour at 100% and measure everything else against it, which is why two recipes become comparable the moment you stop reading cups and start reading percents.
Baker's percentage
Ingredient % = (ingredient weight ÷ flour weight) × 100
Flour is always the 100% base in baking. Everything else is relative to it.
Worked examples
| Flour | Water | Hydration % |
|---|---|---|
| 500 g | 350 g | 350/500 × 100 = 70% |
| 1000 g | 600 g | 60% |
| 400 g | 320 g | 80% |
A 70% hydration dough is wetter than a 60% one, the percent predicts texture before you mix.
Why flour is the 100% base
Unlike "percent of total," baker's % keeps flour fixed at 100% so other ingredients scale against it. Double the flour to 1000 g and every other ingredient doubles too, preserving the ratios. This is how pro bakeries scale from a 1-loaf to a 100-loaf batch from one formula.
Other cooking percents
- Brine: 5% salt by weight of water (50 g salt per 1 kg water).
- Reduction: sauce reduced from 500 ml to 400 ml = 20% reduction.
- Doneness tolerance: a roast aimed at 60°C with ±5% tolerance.
- Starter feeds: often 100% hydration (equal flour and water by weight).
Kitchen Percentages Gone Awry
Using total weight as the base (baker's % uses flour, not the sum); mixing volume and weight (percents need grams); assuming all cooking percents share a base (cooking % can use water or flour depending on context); skipping × 100 (the ratio is a decimal until scaled); confusing baker's % with "of total" (70% hydration is not 70% of the dough's weight); and using cups (volume measurements break the weight-based percent).
Related industry guides
For the rest of the industry cluster, start at the hub: Percentage in Finance Interest. Adjacent: Recipe Scaling Percentage and Percentage in Health BMI.
FAQ
Can baker's percentage exceed 100%? Yes — any ingredient heavier than the flour (e.g., 110% hydration or a 120% preferment) reads above 100%; that's normal in baking, unlike "percent of total" which can't.
What's the flour-as-100% base vs percent-of-total? Baker's % sets flour = 100% so ratios are portable; "percent of total" divides by the sum of all ingredients. They give different numbers for the same recipe — don't mix them.
How do I convert a cup recipe to baker's %? Weigh each ingredient, divide by flour weight ×100. You must weigh (grams), not measure cups, because volume breaks the weight-based percent.
Does hydration % predict crumb or crust? Roughly — higher hydration (75%+) gives a more open crumb; lower (60%) a firmer one. It's a texture predictor before you bake.
Why do some formulas list a 100% hydration starter? A starter fed equal flour and water by weight is 100% hydration; it's the standard reference point bakers build from.
Sources: King Arthur Baking, Baker's percentage; BBC Good Food, Cooking.
Disclaimer: Illustrative. Cooking outcomes also depend on temperature, time, and technique; use as a guide. Informational only.
Sources and references
- King Arthur Baking — Baker's percentagehttps://www.kingarthurbaking.com/
- BBC Good Food — Cookinghttps://www.bbcgoodfood.com/
Maintenance and corrections
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