Baker's Percentage: A Complete Guide
What Is Baker's Percentage?
Baker's percentage is a ratio system used to express bread recipe ingredients relative to the weight of flour. Unlike conventional recipe percentages where all ingredients add up to 100%, in baker's percentage, flour is always 100% and every other ingredient — water, salt, yeast, starter, butter — is expressed as a percentage of that flour weight.
This means baker's percentages for a full recipe will sum to more than 100%. That's not an error — it's the nature of the system. A 75% hydration dough has 100% flour + 75% water + 2% salt + 20% starter = 197% total, but every baker immediately understands what that means for the recipe.
Why Bakers Use This System
Baker's percentage solves a problem that conventional recipe formats create: you can't easily scale a recipe by looking at ingredient weights alone without recalculating everything. Baker's percentage makes scaling trivial.
More importantly, baker's percentage encodes recipe character in immediately readable numbers. A baker who sees "75% hydration" knows instantly: this is a moderately wet dough, good open crumb potential, will require stretch-and-fold, needs a hot Dutch oven. A baker who sees "500g flour, 375g water" has to do the math first. Baker's percentage is the shared language of professional bread baking.
Use the bread hydration calculator to convert between grams and baker's percentages instantly.
How to Calculate Baker's Percentage
The formula for each ingredient:
Baker's % = (Ingredient Weight ÷ Total Flour Weight) × 100
If your recipe uses multiple flours (bread flour + whole wheat, for example), the denominator is the sum of all flour weights combined.
Water: 375g → 375/500 × 100 = 75%
Sourdough starter (100% hydration): 100g → 100/500 × 100 = 20%
Salt: 10g → 10/500 × 100 = 2%
Total dough weight: 985g
Note that 100g of 100% hydration starter contributes 50g flour and 50g water to the dough. The true hydration of the recipe above, accounting for the starter's water, is (375 + 50) ÷ (500 + 50) = 77.3%, not 75%. Some bakers calculate "total flour" and "total water" inclusive of the starter when computing overall hydration.
Reading a Recipe in Baker's Percentages
Once you're fluent in baker's percentages, you can immediately understand what a recipe will produce just from the numbers. Common reference points:
| Ingredient | Typical Range | Notes |
|---|---|---|
| Hydration (water %) | 60–90% | 65% = bagels, 75% = sourdough, 85% = ciabatta |
| Salt | 1.8–2.2% | Below 1.5% = under-seasoned; above 2.5% = too salty |
| Sourdough starter | 10–25% | Higher % = faster rise; lower % = longer, more complex flavor |
| Instant yeast | 0.5–1.5% | 0.5% for slow cold ferment; 1% for same-day |
| Butter (enriched doughs) | 5–20% | 10–15% = brioche-adjacent; 20%+ = brioche |
| Whole wheat substitution | 10–30% | Add 3–5% hydration per 10% whole wheat added |
Scaling Recipes With Baker's Percentage
The power of baker's percentage becomes clearest when scaling. If you have a recipe you love and want to make twice as much — or use a different amount of flour because that's what you have — the calculation is simple:
- Decide how much flour you want to use (your new flour weight)
- Multiply each ingredient's baker's percentage by the new flour weight
- Divide by 100 to get grams
Water (75%): 1000 × 0.75 = 750g
Starter (20%): 1000 × 0.20 = 200g
Salt (2%): 1000 × 0.02 = 20g
Total dough: ~1970g
The baker's percentage calculator handles all of this automatically — enter your target flour weight and the tool outputs the gram weights for each ingredient instantly. This is far faster than working through the math for each ingredient individually.
How Starter Complicates the Calculation
Sourdough starter is a mixture of flour and water, so it contributes to both total flour and total water in the recipe. This creates an important distinction:
- Formula hydration (simpler): calculate water weight ÷ flour weight, not counting the flour and water inside the starter
- True dough hydration (more accurate): total water (including starter water) ÷ total flour (including starter flour)
The difference matters when your starter percentage is high (20%+). A recipe with 100g of 100% hydration starter, 500g flour, and 350g water has a formula hydration of 70% — but the true hydration is (350+50) ÷ (500+50) = 72.7%.
The bread calculator accounts for starter hydration in its calculations so you can see the true dough hydration rather than just the formula hydration. If you use a stiff starter (50–65% hydration) or liquid starter (125%+ hydration), the difference from true hydration becomes even more significant.
Developing Intuition Through Baker's Percentage
The real value of baker's percentage isn't just math — it's building intuition about bread. Once you've baked at 70%, 75%, and 80% hydration, you start to feel the differences in your hands. When you encounter a new recipe as baker's percentages, you'll know before you start how the dough will feel, what technique it requires, and what to expect from the final loaf.
The next time you see a recipe, try converting it to baker's percentages before you start. Note the hydration, the salt level, the starter percentage, and any enrichments. Then ask yourself: does this recipe make sense for the bread it claims to produce? This exercise builds a rapid recipe-reading skill that makes you a more confident and adaptive baker.