Baker’s math (aka baker’s percentages) is a numerical system used to identify ratios in bread recipes. It's a formula that uses the total weight of flour as its centerpiece: The total weight of flour is always treated as 100%, and all other ingredients are measured against that flour weight to convert the recipe into percentages. While ingredient amounts change with different batch sizes, the ratios — that is, the relationship between the flour, water, salt, yeast, and other ingredients — will always remain the same.   

Primarily used in bread-specific applications, baker’s math is indispensable for scaling recipes up or down; for determining batch sizes based on the amount of any given ingredient (how many baguettes can I make with only 20 grams of yeast?); or simply for comparing different recipes. Here's an example of a simple formula using baker's percentages: 

Ingredient % Weight
Flour 100% 500g
Water 66% 330g
Salt 2% 10g
Yeast 1.2% 6g

But as helpful as it is, baker’s math can also get confusing. If you're new to the concept of baker's math and want a straightforward introduction that covers the basics, see our previous baker’s percentage blog post. For a more in-depth guide, we also have our professional baker’s reference page. Here, we’re focusing on some of the questions that we hear on a regular basis. Keep reading to find yours (and if we don’t cover it, add it to the comments below and we’ll get on it). Plus (bonus!), after the questions we have a quiz where you can test your expertise. 

In baker's math, which ingredients are considered "flour"?  

The basic answer is that any flour should be considered flour. Whether whole wheat, rye, all-purpose, "00," or even gluten-free, each and every flour should be counted as part of the total flour amount. (Rolled oats and other flaked products, including cracked grains like rye or corn grits, are generally not categorized as flour. Additionally, sugar is not considered flour.) 

An example: If a bread recipe has 700 grams of all-purpose flour, 200 grams of whole wheat flour, and 100 grams of rye flour, the total flour weight of that recipe is 1,000 grams. Since in baker’s math the total amount of flour is always assigned a value of 100%, the flour portion of this recipe would be written like so: All-purpose = 70%, whole wheat = 20%, rye = 10%.  

Sourdough baguettes, straight from the oven Martin Philip
Sourdough baguettes, 73% hydration in baker's math.

Which ingredients are considered a liquid when calculating hydration?  

While it’s true that many ingredients (such as eggs or oil) may be considered liquids and will change dough consistency, the primary baker’s math consideration for hydration is water. Other liquids that contain a majority portion of water, such as milk or beer, can also be considered as hydration.  

If our dough example above (with 1,000 grams flour) has 700 grams of water and 50 grams of olive oil, the hydration remains 70% (1,000g flour, 700g liquid = 70%). Yes, the addition of oil will soften the dough, but fats — even liquid fats — are not considered hydration. They simply don’t contain significant quantities of water, a key requirement for gluten formation. The same goes for liquid sweeteners (like honey) and melted butter.  

What about ingredients beyond the basics: honey, oats, seeds, etc.?  

Just like with water, yeast, and salt, you should determine the ratios of these sub-ingredients by calculating them against the flour. Using our dough example with 1,000 grams flour: If our recipe calls for 40 grams of honey, the percentage of honey in baker’s math is 4%.  

But this brings us to another question: Are there firm rules that prescribe percentage amounts of water, fat, sugar, yeast, or other ingredients in a bread recipe? Unfortunately, the answer is no. From brioche to baguettes, bakers tend to apply their own standards. Salt is the only exception and can generally be calculated at 1.8% to 2.2%. 

How do I calculate preferments and starters?  

Preferments refer to the portion of flour in any recipe that is fermented before the final mix. If you’ve ever used a biga, poolish, sourdough starter, lievito madre, etc., you’ve worked with prefermented flour.   

So are the flour and water held in preferments accounted for in total hydration and flour in the loaf? Yes. 

In the formula example shown in the table below, the "total formula" section captures everything in the recipe — every gram of flour, every drop of water, every grain of salt. Moving to the right, we see the sub-component sections: the "stiff levain" (preferment) and the "final mix." 

The stiff levain is built with flour and water already included in the total formula. The final mix is everything in the total formula minus the preferment ingredients. Said another way, the final mix ingredients plus the preferment equal the total formula. (Notice how the amount — 1,400 grams — at the bottom of the final mix section is the same as the number at the bottom of the total formula column.)  

It’s particularly helpful to list how much flour is prefermented because any increase or decrease in the amount of prefermented flour will impact the flavor and function of our bread. In the formula example below, I preferment 25% of the total flour. That percentage produces a flavor profile with just enough sourness to complement other ingredients. (Using a spreadsheet makes adjusting these proportions in baker’s math easy and quick.) With bread, common ranges of prefermented flour vary from as little as 10% to as much as 50%, depending on the type of flour, length of fermentation, type of bread, and desired flavor profile. Through testing, you’ll find the sweet spot (or sour note) that you’re looking for! 

Screenshot of a Google Sheet built out with a baker's math formula
Building out a spreadsheet with your formula, like this one for Cranberry-Walnut Bread, makes it easy to adjust total amounts.

Last, one bit of clarification. You’ll see that there is an ingredient line for sourdough culture in the total formula. This is the amount that a baker will pull from their maintenance culture to build the preferment. Because it’s such a small amount, we don’t worry about its tiny contribution to the total hydration or flour (in the case below, it’s only 16 grams for the 1,400-gram batch) in our recipe. 

What percentages are recommended for things like nuts or dried fruit?  

From olives in ciabatta to walnuts in rye or dried figs in a nice sourdough, it’s baker’s choice. Ultimately, the percentage of inclusions is guided by taste, cost, and the functional impact of the ingredient(s) involved. A good starting place for things like walnuts, olives, or dried figs is between 20% and 30%.  

With testing you’ll find a sweet spot where the ingredients support the flavor without weighing down the structure too much. With denser breads, the percentage of additional things like dried fruit and nuts can go quite high (up to 40%) but with more open-crumbed breads, structure will be compromised if you add too much stuff. When looking for a starting point, I often use a quantity of inclusions in a recipe I like as a guide. This Sprouted Grain Pain Rustique in our professional section is a good example.  

Japanese Chocolate Milk Bread Martin Philip
Japanese Chocolate Milk Bread, 30% chocolate chips in baker's math.

What about soakers — how are those calculated?  

With “soakers” (presoaked quantities of water and grain in a seeded sourdough, for example), there are multiple approaches. As with other inclusions, the total quantity of grains added to any formula is variable across styles of bread. It may range from below 20% in a sourdough (which isn’t terribly dense) to over 50% in some of the heartier rye breads (such as Vollkornbrot, for example).  

In terms of how the water for the grains is treated in baker’s math, it varies between bakers. Some roll the total amount of water required to soak the grain into the total hydration of a recipe. Others add a dedicated “soaker water” line to a formula, which gives a clearer idea of the amount of water required for the soaked grain. I tend to break the soaker out as a separate line for better clarity. A good example of this (with baker’s percentages) is our version of Night Moves’ bakery’s Anadama.

Can I use baker's percentages for cakes, cookies, and other bakes beyond bread? 

Generally, I use baker’s math when flour comprises the majority portion of a recipe. So, from baguettes to croissants, sourdough, and brioche, I use baker’s math. With cakes, cookies, and even scones and biscuits I switch over to batch percentages. Batch percentages calculate the percentage portion of each ingredient in comparison to the weight of the total batch (as opposed to the weight of just the flour). To calculate batch percentages, divide the weight of any single ingredient by the total weight of the batch. For example, if you had a pound cake recipe that used flour, butter, eggs, and sugar in equal portions by weight, each would comprise 25% in batch percentages.  

Where can I get a spreadsheet to help me?  

For me, the best way to see how baker’s math works is to use a spreadsheet program such as Google Sheets or Microsoft Excel. Using the spreadsheet format, I can see how everything links together, and I can quickly make changes to old formulas or use an existing recipe as a jumping-off point for something new. There is a learning curve with spreadsheets, but this basic Cranberry-Walnut Bread will be enough to get you started.  

So give it a shot. Relying on our resources, from the pro section to blogs, we’ve got the tools to set you up for success. And, if you’re feeling confident, have a look at the quiz below to test yourself or try out a new skill set.  

Practice problems to experiment with baker's math 

Want to take your baker’s math skills for a spin? Here are a few questions that will test what you’ve learned. I’ll put the answers below. No peeking! 

1) In a recipe with the amounts below, what are the baker’s math percentages? 

All-purpose flour: 560g 
Whole wheat flour: 240g 
Malted wheat flakes: 100g 
Water: 700g
Salt: 16g 
Buckwheat honey: 40g 
Sourdough culture: 20g 

2) In a ciabatta with the following percentages, what are the ingredient amounts for a 3 kilogram batch of dough? 

All-purpose flour: 100% 
Water: 82% 
Salt: 2% 
Instant yeast: .5% 
Olive oil: 5% 

3) In the same formula, if we preferment 30% of the flour in a biga, how much flour is prefermented? 

4) In a brioche formula with the following percentages, what is the maximum batch size if we only have 500g of butter?  

All-purpose flour: 100% 
Water: 50% 
Salt: 2% 
Instant yeast: 3% 
Eggs: 50% 
Butter: 50% 
Sugar: 10% 


1) Baker’s math: 
All-purpose: 70.00% 
Whole wheat: 30.00% 
Flakes: 12.50% 
Water: 87.50% 
Salt: 2.00% 
Honey: 5.00% 
Sourdough culture: 2.50% 

2) Ciabatta ingredient amounts: 
All-purpose: 1,583g 
Water: 1,298g
Salt: 32g 
Instant yeast: 8g 
Olive oil: 79g 

3) Flour in the biga: 475g 

4) Maximum brioche batch: 2,650g 

Still have questions? Drop them in the comments and we'll see if we can help!

Cover photo (Pan de Cristal) by Kristin Teig.

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About Martin Philip

Martin Philip is an award-winning baker and author. His critically acclaimed book, Breaking Bread: A Baker’s Journey Home in 75 Recipes (HarperCollins, 2017), is a Wall Street Journal best seller and was chosen as the best cookbook of 2018 by the New York Book Industry Guild. It won the 2018 Vermont...
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