Baker’s Percentage Explained

Every bread recipe in this library is written in baker’s percentage. If you’ve ever read a recipe that called for “65% water” and wondered 65% of what, this is the answer. The whole system is one rule:

Flour is always 100%. Every other ingredient is expressed as a percentage of the flour weight.

That’s it. The rest of this page is what falls out of that rule — why it scales cleanly, how to read a recipe at a glance, and a few common percentages worth memorizing.

A worked example

Take a standard baguette: 100% flour, 68% water, 2% salt, 0.5% instant yeast. If you have 500g of flour to work with, multiply each percentage by 5:

Notice the percentages don’t sum to 100 — they sum to 170.5%. That’s normal and expected. The percentages aren’t parts-of-a-whole; they’re each independent ratios against the flour. The total of all percentages just tells you how heavy the dough will be relative to the flour: 170.5% means 500g of flour yields about 852g of dough.

Why it scales cleanly

Now double the recipe. Instead of dividing every ingredient by 2 and dealing with awkward fractions, you just change the flour:

The percentages don’t change. The bread doesn’t change. The character of the dough is identical. The only thing that scales is the absolute weight of every ingredient, proportionally. This is the whole reason professional bakeries write recipes this way: a head baker can hand a percentage spec to a junior and they can scale it from a single test loaf to a 50kg production batch without rederiving anything.

The calculator on every bread page is doing this math in real time, in both directions. You can set the OUTPUT (3 loaves at 400g each → flour = ?), or you can set the total DOUGH WEIGHT (1200g of dough → flour = ?) and the calculator works backwards. Same percentages, different framings.

Reading a recipe at a glance

Once you’re fluent in baker’s percentages, you can size up an unfamiliar recipe in about three seconds. The numbers tell you what kind of bread you’re looking at before you even read the method:

• Water percentage tells you the texture. 55-60% = bagels and pretzels (tight, chewy). 65-72% = sandwich loaves and baguettes (balanced). 75-85% = ciabatta, focaccia, pizza (open, holey).
• Salt percentage tells you the seasoning is sane. 1.8-2.2% is the standard band. Below 1.5% the bread tastes flat; above 2.5% it’s salty enough to notice.
• Yeast percentage tells you how long the ferment is meant to run. 0.1-0.3% = overnight cold ferment (a 24-hour Neapolitan pizza). 0.5-1% = same-day, a few hours of bulk. 1-2% = fast, two-hour project.
• Fat percentage tells you how enriched it is. 0% = lean (baguette, sourdough). 3-8% = lightly enriched (sandwich bread, dinner rolls). 30-50% = brioche territory.

A recipe at “100% flour, 60% water, 0.1% yeast, 2% salt” isn’t a yeast bread — it’s a Neapolitan pizza dough. The numbers told you that.

Common percentages worth memorizing

You don’t need a calculator to size up most breads. These few numbers cover the majority of the library:

Converting a cups-based recipe

Most American recipes are still written in cups. Converting one to baker’s percentage is a two-step process: weigh the ingredients (use a scale, your “1 cup of flour” might be anywhere from 120-150g depending on how you scoop), then divide everything by the flour weight and multiply by 100.

Example: a recipe calls for 3 cups flour, 1¼ cups water, 1½ tsp salt, 1 tsp instant yeast. Weighed out:

• Flour: 3 × 125 = 375g
• Water: 1.25 × 237 = 296g
• Salt: 1.5 × 6 = 9g
• Instant yeast: 1 × 3.1 = 3.1g

Now divide each by flour weight and multiply by 100:

• Flour: 100%
• Water: 296 ÷ 375 = 79%
• Salt: 9 ÷ 375 = 2.4%
• Instant yeast: 3.1 ÷ 375 = 0.83%

Now you know the recipe is a high-hydration (79%) bread with a slightly aggressive salt level (2.4%) and standard yeast. You can compare it directly against the ciabatta or focaccia in the library, you can scale it cleanly, and you can dial anything you want — say, drop the salt to 2% or push the hydration to 82% — without having to rederive the entire recipe.

A note on what 100% can mean

Most of the time, “100% flour” means one type of flour: bread flour, AP, or whatever the recipe specifies. But some recipes use a flour blend (50% bread flour + 50% whole wheat is common for country sourdough). The 100% rule still holds — it’s just the total flour that equals 100%, with the blend split written underneath. The calculator in this library handles both cases; when a recipe defines a flour blend, you’ll see two flour rows in the ingredient panel that sum to 100% of the flour line.

Everything else in this site — the hydration explainer, the per-bread method, the calculator UI — assumes you understand this one rule. If you skimmed the rest, just keep this: flour is 100%, everything else is a percentage of flour, and the math scales perfectly in both directions.