Baker's Percentages Explained

Baker's percentages are a way of writing a recipe in which the total flour always equals 100 percent and every other ingredient is expressed as a percentage of that flour weight. A dough with 1,000 g of flour and 700 g of water is 70 percent hydration, no matter how big the batch. Once you think this way, formulas become easy to compare, scale and troubleshoot.

The system only works with weights, so a digital scale is essential. This guide explains how the percentages are calculated, how to scale a formula to any dough size, how to handle preferments and mix-ins, and what typical ranges look like for common breads, so you can tell at a glance whether a recipe is lean, rich, stiff or slack.

How the math works

Pick the total flour weight, including every type of flour in the dough. Divide each other ingredient by that number and multiply by 100. For 500 g bread flour, 350 g water, 10 g salt and 5 g instant yeast, the formula reads: flour 100%, water 70%, salt 2%, yeast 1%.

If a dough uses two flours, they share the 100%. A loaf with 400 g bread flour and 100 g whole wheat flour is 80% bread flour and 20% whole wheat, and the water percentage is still calculated against the full 500 g.

• Flour 500 g = 100%
• Water 350 g = 70%
• Salt 10 g = 2%
• Instant yeast 5 g = 1%
• Total formula = 173%

Scaling a formula to any batch size

To make a dough with a known amount of flour, multiply that flour weight by each percentage. For 800 g of flour with the formula above: 560 g water, 16 g salt, 8 g yeast.

To make a specific total dough weight, add up all the percentages, divide the target weight by that total, and the result is your flour weight. For three 600 g loaves (1,800 g of dough) at 173%, flour is 1,800 ÷ 1.73 ≈ 1,040 g. Then calculate every other ingredient from that. Many bakers add 2 to 3% extra to cover dough lost on the bowl and bench.

Typical ranges for common doughs

Knowing normal ranges lets you read a formula before you mix it. Bagel and pretzel doughs are stiff, around 55 to 60% water. Sandwich loaves sit near 60 to 68%. Rustic and artisan loaves often run 70 to 80%, and ciabatta or focaccia can go higher. Salt almost always falls between 1.8 and 2.2%. Instant yeast in a same-day dough is usually 0.5 to 1.5%; long, cold fermentations use far less.

Enriched doughs add sugar, butter, eggs and milk. Brioche can include 50% or more butter. Remember that milk, eggs and butter all contain water, so a rich dough may feel softer than its listed water percentage suggests.

Handling preferments and mix-ins

When part of the flour and water is in a poolish, biga or sourdough levain, include that flour and water in the totals. A 100% hydration starter of 200 g contains 100 g flour and 100 g water; add those to the main dough's flour and water when you calculate overall hydration and salt. Bakers also express the preferment as a percentage of total flour, for example 20% prefermented flour.

Seeds, nuts, dried fruit and cheese are expressed as percentages of flour too, but they do not count toward the flour total. Soaked grains bring their soaking water, which should be noted separately.

Converting a cup recipe

To translate an old volume recipe, weigh each ingredient as you would normally measure it, then calculate the percentages. Flour weights per cup vary from about 120 to 150 g depending on how it is scooped, which is exactly why percentages are more dependable than cups.

Once you have the percentages, you can compare the recipe to others of the same style. If a supposed artisan loaf turns out to be 58% hydration, you know why it baked tight.

Common questions

Why do the percentages add up to more than 100?

Because only the flour is fixed at 100%. Everything else is added on top of it, so a simple lean dough totals about 170 to 180%, and rich doughs total much more.

Is hydration the same as the water percentage?

In a lean dough with only water, yes. When milk, eggs or a starter are involved, bakers often calculate effective hydration by counting the water those ingredients contain, which is higher than the water line alone.

Do I count yeast and salt as part of the flour?

No. Only flour (including the flour in any preferment) makes up the 100%. Salt, yeast, sugar, fats and liquids are all calculated relative to it.