Baker’s percentage is the lingua franca of professional bread baking. Once you understand it, you can read any professional formula, scale recipes to any batch size, compare bread types at a glance, and build your own formulas from scratch. It’s not complicated — but it works differently from the percentage math you learned in school, and that difference trips up a lot of home bakers.
This guide covers everything: what baker’s percentage is, how to read and write it, how to use it for scaling and hydration adjustment, and reference formulas for common bread types.
What Is Baker’s Percentage?
In standard cooking, percentages are calculated against the total weight of all ingredients. If you have 200g of flour and 50g of sugar in a 400g recipe, the sugar is 12.5% of the recipe.
Baker’s percentage works differently. Flour is always defined as 100%, and every other ingredient is expressed as a percentage of the flour weight — not the total recipe weight. This means the percentages in a bread formula do not add up to 100. They typically add up to 175–200% or more.
Why do it this way? Because flour is the structural foundation of every bread. By anchoring everything to flour weight, you can instantly see the relationships between ingredients regardless of batch size, and you can scale any formula up or down by simply changing the flour weight and multiplying.
Baker’s percentage vs. standard percentage:
| System | Flour (200g) | Water (150g) | Salt (4g) | Total |
|---|---|---|---|---|
| Standard % | 56% | 42% | 1.1% | ~100% |
| Baker’s % | 100% | 75% | 2% | 177% |
The baker’s percentage version tells you immediately: this is a 75% hydration dough with 2% salt. The standard version tells you very little at a glance.
How to Read a Baker’s Percentage Formula
A professional bread formula looks like this:
| Ingredient | Baker’s % |
|---|---|
| Bread flour | 100% |
| Water | 72% |
| Salt | 2% |
| Instant yeast | 0.5% |
| Total | 174.5% |
Reading this formula, you know immediately:
- It’s a 72% hydration dough — moderately high, with decent open crumb potential
- Salt at 2% is standard for a savory lean bread
- Yeast at 0.5% suggests a moderate fermentation speed — not instant, not slow cold proof
To convert this to actual weights, choose your flour amount and multiply:
With 800g flour:
- Water: 800 × 0.72 = 576g
- Salt: 800 × 0.02 = 16g
- Yeast: 800 × 0.005 = 4g
With 1,500g flour:
- Water: 1,500 × 0.72 = 1,080g
- Salt: 1,500 × 0.02 = 30g
- Yeast: 1,500 × 0.005 = 7.5g
The ratios are identical. This is the power of the system.
How to Scale Recipes
Scaling is where baker’s percentage saves the most time. The process has two directions:
Scaling from a known flour weight
This is straightforward — change the flour weight and multiply everything else by the same factor.
Original: 1,000g flour → Target: 600g flour Scaling factor: 600 ÷ 1,000 = 0.6 Multiply every ingredient weight by 0.6.
Scaling from a target dough weight
This is more useful when you’re fitting a recipe to a specific tin, banneton, or batch size. The method:
- Sum all the percentages in the formula (expressed as decimals)
- Divide your target dough weight by that sum — this gives you the flour weight
- Multiply each percentage by the flour weight to get ingredient weights
Example: Target dough weight 1,200g, formula totals 1.745 (174.5% expressed as decimal)
Flour = 1,200 ÷ 1.745 = 688g Water = 688 × 0.72 = 495g Salt = 688 × 0.02 = 14g Yeast = 688 × 0.005 = 3.4g Check: 688 + 495 + 14 + 3.4 = 1,200.4g ✓
This method works for any recipe and any target weight. It’s how bakeries scale formulas from test batches to production.
Reference Formulas for Common Bread Types
The table below gives baker’s percentage reference ranges for common breads. These are starting points — most bakers adjust within these ranges based on their flour, environment, and preference.
| Bread Type | Flour | Water | Salt | Leavening | Other |
|---|---|---|---|---|---|
| Baguette | 100% | 68–72% | 2% | 0.3–0.5% yeast | — |
| Basic sourdough | 100% | 70–75% | 2% | 15–20% starter | — |
| Focaccia | 100% | 80–90% | 2.2% | 0.5% yeast | 5–8% olive oil |
| Ciabatta | 100% | 75–80% | 2% | 0.3% yeast | Optional: 1–2% olive oil |
| Sandwich loaf | 100% | 60–65% | 1.8% | 1% yeast | 3–5% butter, 3% sugar |
| Bagel | 100% | 55–58% | 1.8% | 1% yeast | 1% malt syrup |
| Brioche | 100% | 35–45% | 1.8% | 1% yeast | 40–60% butter, 20–30% eggs |
| Challah | 100% | 50–55% | 1.5% | 1% yeast | 15–20% eggs, 10% oil, 8% sugar |
| Pizza (Neapolitan) | 100% | 58–65% | 2.5% | 0.1–0.2% yeast | — |
| Pizza (New York) | 100% | 62–68% | 2% | 0.5% yeast | 1–2% olive oil |
Note the outliers: brioche has very low water percentage (35–45%) because most of its liquid comes from eggs and the fat in butter. Bagels have extremely low water (55–58%) to produce their distinctive dense, chewy crumb. Understanding these as baker’s percentages makes the intention immediately legible.
Adjusting Hydration Within a Formula
Baker’s percentage makes hydration adjustments trivially easy.
To increase hydration from 68% to 72% on a 1,000g flour recipe:
Additional water = (72 − 68) ÷ 100 × 1,000 = 40g more water No other ingredient changes.
To adjust for a flour swap: If replacing 20% of bread flour with whole wheat, whole wheat absorbs roughly 5–10% more water. On a 1,000g total flour recipe with 200g whole wheat, add approximately 10–15g more water (roughly 1–1.5% of flour weight).
Reverse hydration calculation:
Water needed = (Target hydration% ÷ 100) × Flour weight 72% of 850g flour = 0.72 × 850 = 612g water
Typical Ranges for Salt, Yeast, and Enrichments
Knowing standard baker’s percentages for common ingredients helps you sanity-check any recipe and build your own formulas:
| Ingredient | Typical Baker’s % | Notes |
|---|---|---|
| Salt | 1.8–2.2% | Below 1.5% tastes flat; above 2.5% inhibits yeast |
| Instant yeast | 0.3–1% | Lower for long cold ferments; higher for same-day |
| Active dry yeast | 0.5–1.5% | Slightly higher than instant — needs activation |
| Sourdough starter (100%) | 10–25% | Lower for slow overnight ferments |
| Olive oil | 2–8% | Mostly for focaccia, pizza, some ciabatta |
| Butter | 5–60% | Enriched doughs; higher end = brioche territory |
| Sugar | 2–15% | Slight amounts aid browning; higher = enriched/sweet doughs |
| Eggs | 10–30% | Contributes liquid and fat; reduce water accordingly |
| Milk (replacing water) | 1:1 swap | Adds fat and sugar; slightly reduces effective hydration |
Building Your Own Formula from Scratch
With baker’s percentage, you can design a recipe before you bake it. Here’s a structured approach:
Step 1: Choose your hydration. Start with your target bread type. Use the reference table above as a guide. For a first custom formula, aim for a familiar range (68–74%) before pushing to extremes.
Step 2: Set your salt. Use 2% for most lean breads (baguettes, sourdough, focaccia). Drop to 1.8% for enriched doughs where other flavors are present.
Step 3: Set your leavening. For yeasted breads: 0.3–0.5% instant yeast for an overnight cold ferment; 0.8–1% for a same-day bake. For sourdough: 15–20% starter (100% hydration) for an 8–12 hour bulk.
Step 4: Add enrichments if needed. Express fats, eggs, and sugars as percentages of flour. Remember that eggs and dairy contribute liquid — reduce your water by roughly 50–60% of the egg weight added (the other 40–50% is protein and fat, not water).
Step 5: Calculate to actual weights. Choose your flour weight (500g is a good test batch). Multiply each percentage by the flour weight.
Step 6: Bake, note, adjust. Write down your formula, bake it, and note what you’d change. Adjust one variable at a time. After 2–3 test bakes, you’ll have a formula that behaves exactly as you intend.
Common Baker’s Percentage Mistakes
Calculating against total dough weight instead of flour weight. This is the most frequent error. If you divide water by total dough weight instead of flour weight, every ingredient amount will be wrong — and the error compounds as you scale up.
Forgetting pre-ferment or starter flour and water. If your recipe uses a poolish, biga, levain, or sourdough starter, the flour and water inside that pre-ferment must be added to your totals before calculating percentages. Leaving them out gives you an incorrect hydration figure.
Treating baker’s percentage as a recipe rather than a framework. The percentages define ratios, not a specific loaf. A 72% hydration sourdough formula will behave differently with fresh-milled whole wheat versus aged white bread flour, in a humid summer kitchen versus a dry winter one. Baker’s percentage is your starting point, not your guarantee.
Confusing starter percentage with hydration. The percentage of starter in a formula (e.g., 20% starter) is not the same as the dough’s hydration. The starter contributes both flour and water — you must account for both separately to know the actual dough hydration.
The Bigger Picture
Baker’s percentage is a communication and calculation tool, not a goal in itself. Its value is in the clarity it brings: any baker anywhere, reading the same formula, understands exactly what they’re working with.
Once you’re comfortable reading formulas this way, recipe books become richer resources. You stop following steps mechanically and start understanding the reasoning behind them. You can adjust for your flour, your kitchen, your schedule — and get predictable results because you understand what each number means.
Start by converting one recipe you already make into baker’s percentages. Work out the hydration, salt, and yeast percentages from the gram weights in the recipe. You’ll likely recognize the numbers from the reference table — and that recognition is the moment baker’s math stops being a concept and becomes a tool you actually use.