Professional bakers don’t usually talk about recipes, but rather about formulas. Bread is all about proportions, and baker’s math is a way of breaking down ingredients into these proportions so that you can scale up or down as needed. It also makes baking much easier because, once you understand the basic proportions, you can freely mix and match ingredients to invent all kinds of breads on your own.

It’s not necessary to learn baker’s math to bake good bread, of course, but it can expand your ability to mix and match ingredients and break free of recipes to create your own formulas.

In baker’s math, every ingredient is expressed in titles of the flour weight, which is always expressed as 100 percent. For example, let’s take a typical formula for French bread:

- Flour: 100%
- Water: 66%
- Salt: 2%
- Instant yeast: 0.6%
- Total: 170%

So, let’s say we’ve got 500 grams of flour. If I wanted to make French bread, here’s how I’d figure out the weight of the other ingredients

- Water: 500 * 0.66 = 330 grams
- Salt: 500 * .02 = 10 grams
- Instant yeast: 500 * .006 = 3 grams

We can also first decide how much dough we want, and work backwards. Let’s say we want to make 1 kilogram of dough. First, we need to figure out how much flour we need. To do this, we divide the total of all the ingredient percentages added up (170% = 1.7) into the total weight of the dough: 1000 grams / 1.7 = 588 grams of flour (rounded to nearest gram).

Now that we know the flour weight, we figure out the weight of each of the ingredients by multiplying thier percentage by the flour weight, just as we did above.

- Water = 0.66 * 588 = 388 grams
- Salt = .02 * 588 = 12 grams (rounded)
- Instant yeast = .006 * 588 = 6 grams (rounded)