What Is Baker's Percentage? A Complete Guide
Baker's percentage is the universal language of bread formulas. Here's exactly how it works, why bakers use it, and how to read and write any recipe with confidence.
What Is Baker’s Percentage? A Complete Guide
If you’ve been baking from recipes long enough, you’ve probably run into a formula that looks something like this: 100% flour, 75% water, 2% salt, 20% starter. At first glance it seems strange. How can flour be 100% if there are other ingredients? And why express a recipe as percentages at all when grams work perfectly fine?
Once it clicks, though, baker’s percentage becomes one of the most useful tools you’ll use in the kitchen. It lets you scale recipes up or down instantly, compare formulas at a glance, and diagnose why a dough behaved the way it did. This guide walks through exactly how it works and why it matters.
The Core Idea: Flour Is Always 100%
Baker’s percentage is a system for expressing ingredient quantities relative to the total weight of flour in a recipe. Flour always equals 100%, regardless of how much flour is actually in the recipe. Every other ingredient is expressed as a percentage of that flour weight.
So if a recipe calls for 500g of flour and 375g of water, the water percentage is 375 divided by 500, multiplied by 100. That gives you 75%. In baker’s percentage terms, that dough is 75% hydration.
This is different from the kind of percentage you learned in school, where all parts have to add up to 100. In baker’s math, the total can be well over 100% because every ingredient is calculated against flour independently. A typical sourdough formula might total 200% or more when you add everything up. That’s normal and expected.
How to Calculate Baker’s Percentage
The formula is simple:
Ingredient percentage = (ingredient weight / flour weight) x 100
Here’s a straightforward example using a basic sourdough loaf:
- Bread flour: 450g
- Whole wheat flour: 50g
- Water: 375g
- Sourdough starter: 100g
- Salt: 10g
Total flour is 500g (450g + 50g). Now calculate each percentage:
- Flour: 500 / 500 x 100 = 100%
- Water: 375 / 500 x 100 = 75%
- Starter: 100 / 500 x 100 = 20%
- Salt: 10 / 500 x 100 = 2%
Written as a formula: 100% flour, 75% water, 20% starter, 2% salt.
Notice that water contained in the starter is not counted separately in this simplified version. Advanced formulas use “true hydration” calculations that account for the water and flour in the starter itself, but for most home bakers the straightforward method above is accurate enough.
Why Bakers Use Percentage Instead of Grams
Grams are great for following a specific recipe. But percentages are better for understanding a recipe.
When a formula is written in baker’s percentages, you can immediately see the character of the dough without knowing anything else about it. A 65% hydration dough is firm and easy to handle. An 85% hydration dough is very wet and extensible. A 2.2% salt dough will taste well-seasoned. A 1.5% salt dough will taste mild. You learn to read these numbers the same way an experienced cook reads a spice list.
Percentages also make scaling trivial. If you want to make two loaves instead of one, you don’t need to recalculate every ingredient. You just double the flour weight and apply the same percentages. If you want to bake a smaller test loaf, reduce the flour and the ratios stay exactly the same. The CrumbDesk Recipe Scaler does this automatically — enter your formula once and scale to any batch size without touching the percentages.
Comparing recipes becomes much easier too. If someone posts a formula online with different total flour weights than yours, you can still compare hydration levels, salt content, and starter percentages directly because the proportions are what matter, not the raw gram weights.
Reading a Sourdough Formula
Most well-written sourdough recipes will include baker’s percentages alongside gram weights. Here’s how to read a typical one:
| Ingredient | Weight | Baker’s % |
|---|---|---|
| Bread flour | 400g | 80% |
| Whole wheat flour | 100g | 20% |
| Water | 375g | 75% |
| Starter | 100g | 20% |
| Salt | 10g | 2% |
| Total | 985g | 217% |
The total percentage exceeding 100% is correct. The flour column (80% + 20%) adds to 100% because that’s the baseline. Every other ingredient is measured against that baseline.
A few numbers worth knowing by feel:
Hydration (water percentage): Below 70% produces a stiffer, easier-to-handle dough. 72 to 78% is a common range for country loaves. Above 80% requires confident handling and benefits from techniques like stretch-and-fold. The CrumbDesk Hydration Calculator lets you explore how different hydration levels change your dough before you commit to mixing.
Starter percentage: Most recipes fall between 15 and 25%. Higher starter percentages mean faster fermentation. Lower percentages mean slower, often more complex fermentation. This directly affects your bulk fermentation time, since a dough with 25% starter at 75°F will be ready sooner than the same dough with 10% starter.
Salt percentage: Almost all bread recipes land between 1.8 and 2.2%. Salt affects flavor, gluten development, and fermentation rate. Below 1.8% tends to taste flat. Above 2.2% starts to noticeably inhibit fermentation and can make the crumb tight.
Writing Your Own Formulas
Once you understand baker’s percentage, you can start building formulas from the ratios up rather than from a specific gram weight down. This is how professional bakers work.
Start with a target hydration based on the kind of dough you want. Then choose a starter percentage based on how much time you have and how active your starter is. Pick a salt percentage between 2 and 2.2%. Decide whether you want a 100% bread flour loaf or a blend with whole wheat, rye, or other flours.
Once you have the percentages, pick a flour weight based on how many loaves you want to bake, multiply each percentage through, and you have a custom formula that’s yours.
This is also how you reverse-engineer recipes you find online. If someone posts photos of an incredible open crumb and mentions they used a high-hydration formula, you can look at the listed percentages and understand exactly what made that dough behave the way it did.
A Few Common Pitfalls
Forgetting to add all flours together. If your recipe uses multiple flours, the total flour weight is the sum of all of them. Calculating percentages against just the primary flour will give you wrong numbers.
Confusing baker’s percentage with volume measurements. Baker’s percentage only works with weights. Cups and tablespoons don’t translate reliably because density varies. If a recipe you want to analyze only lists volume measurements, convert to grams first.
Assuming starter hydration doesn’t matter. A 100% hydration starter (equal parts flour and water by weight) contributes roughly equal amounts of each to your dough. A stiffer starter or a more liquid one changes the true hydration of your formula. For casual baking this is a small effect, but if you’re trying to hit a precise hydration level it’s worth accounting for.
Baker’s percentage is one of those tools that feels slightly abstract until suddenly it doesn’t. Most bakers reach a point where they can look at a formula and immediately understand the dough it will produce before mixing a gram of anything. That fluency is worth developing.
If you want to see baker’s percentage in action for your own recipe, the CrumbDesk Hydration Calculator lets you enter your ingredients and instantly see your hydration percentage alongside the water weight you need for any target ratio.
FAQ
Do I need to use baker’s percentage to bake good bread? No. Plenty of excellent bakers work entirely from gram weights in tried-and-true recipes. Baker’s percentage is a tool for understanding and flexibility, not a requirement. But once you learn it, you’ll find it hard to read a recipe any other way.
Why is flour always 100% even when other ingredients weigh more? Flour is the foundation of almost every bread recipe. Expressing everything relative to flour makes comparisons consistent across recipes of any size. It’s a convention the professional baking world standardized on decades ago, and it works because flour weight is the single variable that most directly determines yield.
What is a good hydration percentage for a beginner? Most beginners do well starting around 70 to 72%. The dough is workable, holds its shape reasonably well, and still produces an open crumb with proper fermentation. Once you’re comfortable with the handling, you can experiment with pushing hydration higher.
How does baker’s percentage relate to hydration percentage? They’re the same system. Hydration percentage is just the baker’s percentage applied specifically to water. When someone says their dough is “75% hydration,” they mean the water weight is 75% of the flour weight.
Can I use baker’s percentage for non-sourdough bread? Yes. Baker’s percentage is used across all bread baking — yeasted sandwich loaves, enriched doughs, flatbreads, pizza. Anywhere flour is the primary ingredient, the same system applies.
What does “true hydration” mean? True hydration accounts for the flour and water contained within the sourdough starter itself, rather than treating the starter as a single ingredient. Since a 100% hydration starter is 50% flour and 50% water, a recipe with 100g of starter actually contains 50g of flour and 50g of water from that starter alone. True hydration factors those contributions into the overall percentage. For most home baking the difference is small, but it matters when you’re trying to hit a precise target.
How do I scale a recipe up using baker’s percentage? Decide how much flour you want to use for your new batch size. Then multiply that flour weight by each ingredient’s percentage divided by 100. For example, if you want to bake with 800g of flour and your recipe calls for 75% water, you need 800 x 0.75 = 600g of water. The CrumbDesk Recipe Scaler handles all of this automatically if you’d rather not do the math by hand.