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Baker's Percentage Explained

Sourdough basics · 6 min read

Every professional bread recipe is written in baker's percentage. Once you understand it, you can scale any recipe to any size, compare recipes at a glance, and adjust ingredients with confidence. It takes about five minutes to learn and you'll use it every time you bake.

The core idea

In normal cooking, percentages are based on the total weight of everything combined. In baker's math, everything is expressed as a percentage of the flour weight — not the total dough weight. Flour is always 100%.

Flour = 100%. Always. Every other ingredient is a percentage of that flour weight.

This is different from how most people think about percentages, which is why it trips people up at first. But the reason bakers do it this way is practical: flour is always the biggest ingredient, it's always present, and it's the most stable reference point. Once you fix flour as your anchor, every other number tells you something immediately useful.

A simple example

Basic sourdough recipe

IngredientGramsBaker's %
Bread flour500g100%
Water375g75%
Starter100g20%
Salt10g2%
Total985g

Each percentage is calculated by dividing the ingredient weight by the total flour weight and multiplying by 100:

Why this makes scaling trivial

The reason baker's percentage is so powerful is that once you have the percentages, you can produce any batch size instantly. Say you want to make two loaves instead of one, targeting 900g of dough per loaf (1800g total).

From the percentages above, the total is 100 + 75 + 20 + 2 = 197% of flour. So:

The ratios are identical. The bread will behave and taste exactly the same. Our calculator does this instantly — just enter your target dough weight and it recalculates everything.

What the percentages tell you instantly

Once you're familiar with typical ranges, glancing at a recipe's percentages tells you a lot before you even start mixing:

IngredientTypical rangeWhat it signals
Water (hydration)65–85%How wet/sticky the dough will be
Starter / levain10–30%How quickly the dough will ferment
Salt1.8–2.2%Flavour and gluten strengthening
Whole wheat / rye10–30%Earthier flavour, denser crumb

Multiple flours — the important rule

When a recipe uses more than one type of flour, baker's percentage is based on the combined total flour weight, not each flour separately.

Mixed flour example

IngredientGramsBaker's %
Bread flour450g90%
Whole wheat flour50g10%
Total flour500g100%
Water375g75%
Starter100g20%
Salt10g2%

The total flour is 500g. All other percentages are still relative to that 500g total — not to the individual flour amounts.

Baker's % vs. normal percentage — the key difference

In baker's math, the percentages can add up to more than 100%. In the example above, 100 + 75 + 20 + 2 = 197%. This confuses people who expect percentages to always sum to 100.

This is correct and intentional. The percentages don't represent "shares of the total" — they represent ratios relative to flour. Think of it as a recipe language rather than a statistical breakdown.

Don't want to do the math?

Our sourdough calculator shows baker's percentage for every ingredient in real time as you type. Enter your recipe once and it handles all scaling, hydration adjustment, and starter conversion automatically.

Try it with your own recipe — baker's % shown live as you type.

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