Baker's percentage: a practical introduction

Baker's percentage expresses every ingredient as a percentage of the flour weight. Flour is always 100 percent, even though the finished dough contains additional mass from water, salt, starter, yeast, or other ingredients.

The calculation is:

Ingredient percentage = ingredient weight ÷ flour weight × 100

If a formula contains 500 grams of flour and 350 grams of water, the water percentage is 350 ÷ 500 × 100 = 70 percent. Ten grams of salt in the same formula is 10 ÷ 500 × 100 = 2 percent.

Why the percentages do not total 100

Flour is a reference quantity, not a share of a fixed pie. A formula with flour at 100 percent, water at 70 percent, and salt at 2 percent totals 172 percent. That simply means the total dough weight is 1.72 times the flour weight.

With 500 grams of flour, the example is:

• Flour: 500 g
• Water: 350 g
• Salt: 10 g
• Total: 860 g

The total can also be calculated as 500 × 1.72 = 860 grams.

Scaling from one number

Once a formula is written as percentages, select the new flour weight and calculate every other ingredient from it. To scale the example from 500 grams of flour to 800 grams:

• Water: 800 × 0.70 = 560 g
• Salt: 800 × 0.02 = 16 g
• Total dough: 800 + 560 + 16 = 1,376 g

The ratios are unchanged because each ingredient is recalculated from the same flour reference. This avoids repeatedly converting or rounding separate cup measures.

Hydration is one baker's percentage

Hydration is the water weight divided by the flour weight. It is useful because it lets readers compare formulas with different batch sizes. A 70-percent-hydration formula has 70 grams of water for every 100 grams of flour, whether the batch uses 300 grams or 3,000 grams of flour.

Hydration alone does not predict every handling detail. Different flours absorb water differently, and temperature, mixing, and fermentation also matter. Treat hydration as a precise ratio inside the formula, not as a guarantee of a specific texture.

Including preferments and starters

When a preferment contains flour and water, those quantities can be included in the formula totals. For example, 100 grams of a starter maintained at equal weights flour and water contributes 50 grams of flour and 50 grams of water.

Suppose the main dough lists 500 grams flour, 350 grams water, and 100 grams of that starter. Total flour is 550 grams and total water is 400 grams. The total-formula hydration is 400 ÷ 550 × 100 = about 72.7 percent.

A recipe may state hydration using only the main-dough flour and water, or it may include the preferment. Neither convention should be assumed silently; check how the recipe defines its percentage.

What baker's percentage does not solve

Preserving ingredient ratios does not automatically preserve pan depth, heat transfer, fermentation time, or baking time. Scaling the formula and scaling the physical process are related but separate tasks.

Use baker's percentage to make the ingredient math explicit. Then follow the source recipe’s guidance for pans, temperature, fermentation cues, and doneness. The method is valuable because it makes one part of the problem—the formula ratios—easy to inspect and reproduce.