Why bakers write recipes as percentages
A home recipe says "500 g flour, 350 g water". A bakery formula says "100% flour, 70% water" — and that second version survives contact with reality. It scales from one loaf to fifty without recalculating anything, it lets you compare two recipes at a glance (is this dough wetter than the one I made last week?), and it makes the levers explicit: hydration, salt and yeast each become a single number you can reason about.
The rule is simply: every ingredient ÷ total flour × 100, and flour is always 100%. That's why the column adds up past 100 — the percentages aren't slices of the dough, they're ratios to the flour. A basic loaf totalling 171% means the dough weighs 1.71× its flour, which is exactly the number you divide by when scaling to a target batch.
Three reference formulas
Each shown at 500 g of flour, computed by the calculator's engine:
Lean white loaf — 171% total, 855 g of dough
| Ingredient | Baker's % | At 500 g flour |
|---|---|---|
| Bread flour | 100% | 500 g |
| Water | 68% | 340 g |
| Salt | 2% | 10 g |
| Instant yeast | 1% | 5 g |
Rustic high-hydration — 181% total, 903 g of dough
| Ingredient | Baker's % | At 500 g flour |
|---|---|---|
| Bread flour | 90% | 450 g |
| Whole wheat flour | 10% | 50 g |
| Water | 78% | 390 g |
| Salt | 2% | 10 g |
| Instant yeast | 0.6% | 3 g |
Enriched soft dough — 190% total, 951 g of dough
| Ingredient | Baker's % | At 500 g flour |
|---|---|---|
| Bread flour | 100% | 500 g |
| Milk | 55% | 275 g |
| Butter | 12% | 60 g |
| Sugar | 10% | 50 g |
| Egg | 10% | 50 g |
| Salt | 2% | 10 g |
| Instant yeast | 1.2% | 6 g |
Scaling to the batch you actually want
Three questions come up, and the calculator answers all of them. "I have this much flour" is the simple direction — multiply through. "I want this much dough" runs backwards: divide the target by the formula's total percentage, because dough weight = flour × total%. "I want N loaves of this size" is the same calculation with the target computed for you. Add a little for the dough left in the bowl and on the bench — professional bakeries build in 1–2% loss, which is worth copying if your loaves must hit an exact weight.
Where percentages need care
- Multiple flours share the 100%. With 90% bread flour and 10% whole wheat, the 100% is their sum — so a 78% hydration is measured against all the flour, not just the white.
- A sourdough starter hides flour and water. Ignore that and your calculated hydration runs several points low; the sourdough hydration calculator splits it correctly.
- Not every liquid is hydration. Milk, eggs and butter all carry water, but only partly — our hydration figure counts unambiguous liquids and leaves the judgement calls to you rather than quietly guessing.
- Percentages don't scale technique. A 3× batch needs the same fermentation judgement and a bigger bowl; the numbers scale, the dough's behaviour doesn't always follow.
Changing yeast type as well as batch size? The yeast converter handles fresh, active dry and instant, and the cups to grams converter turns a volume-measured recipe into the weights this calculator needs.