Baker’s Percentage refers to a standard measurement used in most professional kitchens for yeast-raised products. It refers to the ingredients’ ratio to the amount of flour by weight, where flour or the combination of different flours always add up to 100%.

For example if you have 20g of salt to 1 kg of flour, salt is 2% of the weight of the flour. (N.B. salt is usually between 1.5-2.5% of flour weight.)

Another example, if you have 600g of water to 1 kg of flour, water is 60% of the weight of the flour, we can say that the bread is of 60% hydration.

It’s important to note that the formula’s total percentage will not add up to 100%, only the weight of the flour would. Depending on the number of ingredients, each recipe will have a different total percentage. Say you have a recipe for a bread that has: 100% flour, 60% water, 2% salt and 2% yeast, you would have a total of 164%.

If ever you come across recipes that only have the percentages and not the weight, and you want to know how much of each ingredient you need, you can easily calculate it. First, you need to figure out how much dough you want to make. For instance, my stand mixer works well with 1.5 kg of dough. You would first divide the total weight of the dough you wish to make, in this case it’s 1.5 kg by the total percentage of 164%.
1500/164 = 9.15
To find the weight of flour you need, multiply 9.15 by 100 = 915 g
To find the water you need to multiply 9.15 by 60 = 549 g and so on…

Easy, right?!

Reference
Myhrvold, Nathan and Migoya, Francisco. (2017) Modernist Bread. Bellevue, WA: The Cooking Lab.
Hamelman, J. (2012). Bread: a bakers book of techniques and formulas. Hoboken, NJ: Wiley.
Hitz, Ciril. (2012). Baking artisan pastries and breads: sweet and savour baking for breakfast, brunch, and beyond. Beverly, Massachusetts: Crestline.
Migoya, Francisco. (2010). The Modern Cafe. Hoboken, NJ: John Wiley & Sons.
Reinhart, Peter. (2010). The Bread Baker’s Apprentice: Mastering the art of extraordinary bread. Berkeley, California: Ten Speed Press
Reinhart, Peter. (2009). Peter Reinhart’s artisan breads every day. Berkeley, California: Ten Speed Press
Hitz, Ciril. (2008). Baking artisan bread: 10 expert formulas for better bread at home. Beverly, Massachusetts: Quarry.
Reinhart, Peter. (2006). Crust and Crumb: master formulas for serious bread bakers. Hong Kong: Ten Speed Press