Baker's Math 101: How to do Baker's Math
Learn how to do Baker’s Math without fear.
Whether you love it or loathe it, math is a vital part of baking. Read through this step-by-step guide with helpful FAQ to become a pro at confidently reading a dough formula and calculating baker’s percentages, including hydration.
If you want a quick and interactive version of this guide complete with quizzes, check out this Baker's Math 101 Instagram Story!
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Baker’s Math: Introduction
Baker’s Math is my favorite math.
I have to be honest: I did not enjoy math until I started baking with it. I used to cry during multiplication tests in the third grade because the numbers just didn’t make sense in my head or on my paper. Without a calculator? Forget it.
Then, I started doubling or halving recipes, which meant multiplying or dividing fractions, so I got a little bit more lenient on my whole “I hate math” thing. Emphasis on “a little bit.”
Now I bake sourdough, and I use math every day with joy. My journey with baker’s math and the baker’s percentage started when I noticed other bakers on Instagram posting beautiful breads with all kinds of numbers beneath—72% hydration, 15% starter, etc. Though initially I was lost, I grabbed my calculator and taught myself what those numbers mean and how to figure them out. Now I want to teach you, too.
Three Reasons to Learn Baker’s Math
You can predict a bread’s behavior based on some of the percentages. Rising times, crumb structure, and more information can be gleaned from these values.
You can quickly communicate facts about your dough formula with other bakers, and understand the formulas that other bakers are using.
You can easily change the quantity of bread that you will end up with without changing the proportions of the recipe. This is called scaling a recipe.
For the purposes of this article, we’re going to focus on sourdough bread recipes, but the same information applies to yeasted bread.
Bread recipes are most easily written as a dough formula.
A dough formula is a list of all ingredients needed to make a loaf of bread that can be quantified by weight, by baker’s percentage, or both. Baker’s math is simply the process of calculating these percentages.
Confused? Don’t worry, we’ll break it down together.
What’s most important to note is that we’re not talking about ingredient quantity by volume here: baking bread by weight is highly preferred, and much more accurate.
If you’re looking for a kitchen scale, here is the one I use.
What is a Baker’s Percentage?
A baker's percentage is a dough formula expressed where the total weight of the flour represents 100%, and all other ingredients are compared by weight to that total and expressed as a percentage.
When a dough formula is written with weight measurements like grams or ounces, it gives you the exact quantity of each ingredient to include in your dough to make a specific size loaf (or loaves) of bread.
When it’s written with percentages, a dough formula gives you the ratio of each ingredient in proportion to the flour so that you can scale the recipe up or down to fit your needs. When given a dough formula written this way, the same loaf of bread can be made in your home kitchen or scaled up to produce 500 loaves in a commercial bakery. Plus, there is a lot of valuable information about how a bread will behave within the baker’s percentages, which is the advantage of getting comfortable reading them even if you don’t intend to increase or decrease a recipe’s size.
If you’re a mental math person, fantastic, you’re a step ahead of the game. If not, get out your calculator or your pencil and paper, because we’re about to do some basic baking math.
Example 1: Basic White Sourdough Bread
makes two loaves
| Ingredient | Weight | Baker's Percentage |
|---|---|---|
| Bread flour | 1000 grams | 100% |
| Water | 700 grams | 70% |
| Sourdough starter (ripe) | 200 grams | 20% |
| Salt | 20 grams | 2% |
This is a basic dough formula for two loaves of white sourdough. The table above lists each ingredient, the weight of that ingredient needed to make two loaves, and the baker’s percentage of each ingredient. Let’s dive into the math.
How to Do Baker’s Math
First, you might notice that the numbers in the Baker’s Percentage column don’t add up to a neat 100%—don’t worry, they aren’t supposed to.
Let’s go over the definition of a baker’s percentage one more time:
“A baker’s percentage is a dough formula expressed where the total weight of the flour represents 100%, and all other ingredients are compared by weight to that total and expressed as a percentage. ”
Whether you have one type of flour or ten, when you add together all of the percentages for the amounts of flour you will get100%. Then, every other ingredient will have its own percentage.
To include starter or not?
Before we move on, I want to address one thing quickly: there are technically two ways to look at calculating baker’s percentages and both are useful. I believe that if you learn the easier way, then you can quickly figure out the slightly more complicated version. What’s the difference between them?
The easier version of baker’s math does not include the weight of the flour and water contained in your sourdough starter when calculating percentages. The slightly more complicated version takes the amount of flour and water in the starter into account when calculating the percentages.
In this tutorial, we’re going to focus on the easier version, which does not include the weight of flour and water from your sourdough starter in the totals.
Step 1: Find the total weight of the flour.
When creating a list of baker’s percentages for a recipe, you always start with finding the total weight of the flour. This number is equal to 100%.
In the case of the recipe above, there is only one type of flour: 1000 grams of bread flour. We’ll tackle recipes with multiple flours later in this article.
We know that the total weight of the flour is 1000 grams. The total weight of the flour is always the number that represents 100%, so for this formula, 1000 grams = 100%.
Next, we want to calculate the percentages of the other ingredients of this dough formula.
To calculate a percentage, you take the number of the ingredient you want to calculate the percentage for and divide it by the number that represents 100%. Then, multiply that number, which is most likely a decimal, by 100 to get the percentage.
The formula for calculating a baker’s percentage is:
(weight of ingredient ÷ weight of flour) x 100 = baker’s % of that ingredient
Step 2: Calculate the Hydration
In bread baking, hydration refers to the amount of water (or liquid) in comparison to the amount of flour, expressed as a percent.
To do this, we take the weight of the water (or liquid), divide it by the weight of the flour, and multiply this number by 100. This gives us the hydration in a percentage. Remember, the formula looks like this:
(weight of water ÷ weight of flour) x 100 = hydration %
Now let’s calculate the hydration of this dough. The recipe uses 700 grams of water.
700 grams water ÷ 1000 grams flour = 0.7
0.7 x 100 = 70% hydration
That wasn’t so bad, right? The same math applies to the starter.
200 grams starter ÷ 1000 grams flour = 0.2
0.2 x 100 = 20% starter
The salt is calculated in exactly the same way.
20 grams salt ÷ 1000 grams flour = 0.02
0.02 x 100 = 2% salt
A helpful hint: almost all bread recipes will include about 2% salt. Some doughs, such as pizza dough, may go up to 3%, but 2% is most common.
Calculating Baker’s Percentages with more than one flour
Let’s look at a different dough formula. We are going to calculate the baker’s percentages.
Example 2: Whole Wheat Sourdough Bread
makes one loaf
| Ingredient | Weight | Baker's Percentage |
|---|---|---|
| Bread flour | 300 grams | ? |
| Whole Wheat Flour | 200 grams | ? |
| Water | 360 grams | ? |
| Sourdough starter (ripe) | 50 grams | ? |
| Salt | 10 grams | ? |
Step 1: Find the total weight of the flour.
Since there are two flours—bread flour and whole wheat flour—we will add those quantities together.
300 grams bread flour + 200 grams whole wheat flour = 500 grams flour total
We can figure out the percentage of each flour the same way we calculate all baker’s percentages: by comparing them to the total weight of flour.
300 grams bread flour ÷ 500 grams flour total = 0.6
0.6 x 100 = 60% bread flour
200 grams whole wheat flour ÷ 500 grams flour total = 0.4
0.4 x 100 = 40% whole wheat flour
This formula contains 60% bread flour and 40% whole wheat flour, for a total of 100% when added together. Whether you use one type of flour or ten, the percentages of each type of flour should always add up to 100%.
Step 2: Calculate the hydration.
360 grams water ÷ 500 grams flour = 0.72
0.72 x 100 = 72% hydration
Step 3: Calculate the percentage of starter.
50 grams starter ÷ 500 grams flour = 0.1
0.1 x 100 = 10% starter
Step 4: Calculate the percentage of salt.
10 grams salt ÷ 500 grams flour = 0.02
0.02 x 100 = 2% salt
Here is the completed dough formula with the baker’s percentages we calculated:
Example 2: Whole Wheat Sourdough Bread
makes one loaf
| Ingredient | Weight | Baker's Percentage |
|---|---|---|
| Bread flour | 300 grams | 60% |
| Whole Wheat Flour | 200 grams | 40% |
| Water | 360 grams | 72% |
| Sourdough starter (ripe) | 150 grams | 30% |
| Salt | 10 grams | 2% |
How to Use Baker’s Percentages
As I mentioned in the introduction, your effort to learn and understand baker’s percentages will pay off in your baking. The first advantage is that you will be able to understand a good amount about your bread’s behavior by looking at the percentage column.
Understanding a bread’s behavior
Let’s talk about hydration first.
The general consensus is that a higher hydration results in a more open crumb, but also a dough that can be trickier to work with. A lower hydration bread may have a more closed crumb but will be easier (less slack) to handle.
Breads made with 100% white flour tend to have the most open crumb, while bread that contains more whole grains usually have a more closed or tighter texture. Whole grains also tend to have the capacity to absorb more water, so a 75% hydration white bread dough will be wetter than a 75% hydration whole wheat dough.
Another thing we can glean from a dough formula is a rough estimate of rising times. A sourdough bread made with 10% starter could take 6-12 hours to go through bulk fermentation, whereas one with 20% starter may only take 3-6 hours. There are environmental factors that come into play, too, but the general pattern is that less starter or yeast will result in longer rise times, and more starter or yeast will speed the process up.
When bread nerds (read: me) get together and discuss their formulas, it’s helpful to be able to share your percentages. There’s not necessarily a “right” way to do things, but understanding the patterns across different recipes will help you become a better baker overall.
Scaling a dough formula
One of the biggest advantages of understanding a dough formula is that you can infinitely scale a recipe up or down based on the yield you’d like to achieve. A single loaf of bread usually contains about 300-500 grams of flour. If you have the percentage of every other ingredient, you simply start with as much flour as you’d like to use, then multiply every other ingredient by the percentage it’s given and there you have it: a scaled recipe.
Example 3: Sourdough Focaccia - Bakery Quantity
| Ingredient | Weight | Baker's Percentage |
|---|---|---|
| Bread flour | 8000 grams | 100% |
| Water | 7200 grams | 90% |
| Sourdough starter (ripe) | 1200 grams | 15% |
| Olive Oil | 300 grams | 3.75% |
| Salt | 160 grams | 2% |
As much as I’d love to surround myself with loaves upon loaves of focaccia, I don’t have the space or bakery equipment to handle that much dough. This formula doesn’t tell us the total quantity of loaves it makes, but I know I can use 500 grams of flour to make one large loaf of focaccia, so let’s scale based on that quantity.
500 grams bread flour = 100%
To calculate the remaining ingredient quantities, we’ll express each percent as a decimal and multiply:
For 90% hydration:
500 x 0.90 = 450 grams water
For 15% starter:
500 x 0.15 = 75 grams sourdough starter
For 3.75% olive oil:
500 x 0.0375 = 18.75 grams olive oil
For 2% salt:
500 x 0.02 = 10 grams salt
That’s it! Now we can rewrite the dough formula for a home baker’s quantity.
Example 3: Sourdough Focaccia - Home Baker's Quantity
makes 1 loaf
| Ingredient | Weight | Baker's Percentage |
|---|---|---|
| Bread flour | 500 grams | 100% |
| Water | 450 grams | 90% |
| Sourdough starter (ripe) | 75 grams | 15% |
| Olive Oil | 18.75 grams | 3.75% |
| Salt | 10 grams | 2% |
Though math has never been my strong suit, it’s become a vital part of my baking routine. Hopefully, I’ve convinced you that it can be part of yours, too. This guide is meant to be a starting point in your baker’s math journey, as there are many recipes out there with more complicated, less whole numbers. The beauty is, once you understand the process, you can use the same calculations for every dough formula you come across, whether it has four ingredients or forty. Even the most math-phobic can agree: when it comes to good bread, anything is worth it.
Ready to bake?
Start with the most popular recipe on Bread & Basil: the Beginner’s Sourdough Bread.