What baker's percentage actually measures
Baker's percentage measures every ingredient against the flour, not against the finished dough. Flour is defined as 100%, and each other ingredient is written as its weight divided by the flour weight. A formula written as 70 / 2 / 1 means 70% water, 2% salt and 1% yeast — 700 g of water, 20 g of salt and 10 g of yeast for every kilogram of flour.
The percentages therefore add up to more than 100. That looks wrong the first time you see it, and it is the single most common stumbling block. The total in this example is 173%, and that number is useful in its own right: it is the dough yield, the weight of dough you get per unit of flour. One kilogram of flour makes 1.73 kg of dough.
Why measure against flour rather than against the total? Because flour is the ingredient that behaves. Every functional property of a dough — how much water it will absorb, how fast it ferments, how much salt it needs to taste seasoned — scales with the flour, not with the batch size. Fix the ratios to flour and a formula becomes portable: it survives being scaled up, being split across mixers, and being handed to somebody who has never made it.
Two conventions matter. First, all flours together make up the 100%. If a formula uses 800 g bread flour and 200 g whole rye, the flour is 1,000 g and the rye is separately noted as 20% of total flour. Second, everything is weighed, never measured by volume. A cup of flour varies by more than 20% depending on how it was scooped, which destroys the arithmetic before it starts. If you only own cups, convert first with the ingredient weight to volume calculator and then work in grams.
The two directions the formula runs in
There are only two calculations, and they are inverses of each other.
Forward, from flour. You know your flour weight F and you have percentages. Each ingredient weight is W = F × P ÷ 100. The total dough weight is D = F × S ÷ 100, where S is the sum of every percentage including flour's own 100.
Backward, from dough. This is the one bakeries actually use. You know you need a specific weight of dough — 40 baguettes at 350 g is 14,000 g — and you need to know how much flour to weigh out. Rearranging the same equation gives F = D × 100 ÷ S. Everything else follows from F as before.
The backward direction is where people improvise and get it wrong. The tempting mistake is to divide the target dough weight by 100 and multiply by each percentage, which treats the percentages as though they were shares of the dough. They are not; they are ratios to flour. On a 173% formula that error inflates every ingredient by 73%, and the dough comes out at 2,993 g instead of 1,730 g.
If you want to convert an existing recipe into percentages, divide each ingredient weight by the flour weight and multiply by 100. Do that once for a recipe you like and you can scale it forever. It is the same arithmetic the recipe scaling calculator performs on non-bread recipes, but anchored to flour instead of to servings.
Worked example: 24 dinner rolls at 90 g each
You want 24 rolls scaled at 90 g apiece, using a straightforward formula of 70% water, 2% salt and 1% instant yeast. Work it through on paper.
- Find the dough weight you need. 24 × 90 g = 2,160 g.
- Add up the percentages. 100 (flour) + 70 (water) + 2 (salt) + 1 (yeast) = 173%.
- Solve for flour. F = 2,160 × 100 ÷ 173 = 1,248.55 g. In a bakery you would round this to 1,250 g and accept a 2 g surplus of dough.
- Water. 1,248.55 × 0.70 = 873.99 g.
- Salt. 1,248.55 × 0.02 = 24.97 g.
- Yeast. 1,248.55 × 0.01 = 12.49 g.
- Check. 1,248.55 + 873.99 + 24.97 + 12.49 = 2,160.00 g. The four weights sum back to the target, which is the only proof you need that the arithmetic is right.
Run the same formula forward from a round 1,000 g of flour instead and you get 700 g water, 20 g salt, 10 g yeast and 1,730 g of dough — enough for 19 rolls at 90 g with 20 g left over. That is the trade-off in practice: round the flour and accept an odd piece count, or round the piece count and accept an awkward flour weight. Bakeries almost always fix the piece count, because the sales figure is the constraint.
Note what the check step does not catch: it confirms the arithmetic, not the formula. A dough at 70% hydration with 2% salt will sum correctly whether or not 70% is the right hydration for your flour. For that judgement, use the dough hydration calculator and the water absorption figure on your flour's spec sheet.
How to read the numbers you get back
Read the total formula percentage first. It tells you the dough yield and it is the fastest sanity check available: a lean bread dough lands near 170-175%, a stiff bagel dough near 155%, and an enriched brioche can exceed 230% because butter, eggs and sugar all pile on top of the flour. If your total is 105%, you have entered percentages as shares of the dough instead of ratios to flour.
Read salt next, because it is the number with the narrowest useful band. Standard professional baking texts put bread salt at roughly 1.8-2.2% of flour weight. Below about 1.5% the crumb tastes noticeably flat and the dough slackens; above about 2.5% fermentation slows enough that your timings stop matching the book. Salt is also the ingredient most often mis-scaled, because 2% of a small batch is a number small enough to fat-finger.
Read yeast as a rate control, not as a fixed quantity. Instant dry yeast at 1% of flour is a brisk same-day dough; at 0.3% it is a long, cool fermentation. If you are switching between instant, active dry and fresh yeast, the percentages are not interchangeable — convert them with the yeast conversion calculator before entering a figure here.
Finally, read the hydration against your flour rather than against a photograph. A strong bread flour at 12.5% protein will comfortably take 72-75% water; a soft supermarket all-purpose flour at 10% protein will be soup at the same number. The percentage that produced a beautiful crumb in someone else's kitchen is a starting point, not a target.
Typical baker's percentages by dough type
| Dough | Water | Salt | Instant yeast | Fat | Sugar | Total |
|---|---|---|---|---|---|---|
| Baguette, lean | 66% | 2.0% | 0.5% | — | — | 168.5% |
| Country sourdough | 75% | 2.0% | 20% levain | — | — | 197.0% |
| Neapolitan pizza | 60% | 2.8% | 0.2% | — | — | 163.0% |
| Focaccia | 80% | 2.0% | 0.6% | 6% | — | 188.6% |
| Sandwich pan loaf | 62% | 2.0% | 1.2% | 6% | 8% | 179.2% |
| Bagel | 53% | 2.0% | 0.5% | — | 3% malt | 158.5% |
| Brioche | 50% (egg and milk) | 2.0% | 1.5% | 55% butter | 12% | 220.5% |
Ranges follow standard professional baking practice as set out in the texts listed under Sources; each total is simply the row's percentages added to flour's 100%. Treat every row as a starting point for your flour, not a specification.
A levain is leaven, flour and water at the same time
When you enter a sourdough levain as, say, 20% in the yeast field, this calculator treats its whole weight as an addition on top of the flour. That is the correct way to size the mix, and it is how most published formulas are written. It is not the correct way to state the dough's true hydration, because the levain is itself part flour and part water.
A 200 g levain at 100% hydration carries 100 g of flour and 100 g of water. Counted properly, the flour in the formula is 1,100 g rather than 1,000 g, and the water is 800 g rather than 700 g — a true hydration of 72.7%, not 70%. Split the levain first with the sourdough starter hydration calculator whenever you need the real figure.
Mistakes that break a baker's percentage calculation
- Treating percentages as shares of the dough. They are ratios to flour. This is why the totals exceed 100%, and why dividing the target dough weight by 100 gives the wrong answer.
- Leaving one flour out of the 100%. Rye, semolina, malted flour and the flour inside a preferment all count. Miss one and every other percentage is overstated.
- Weighing by volume. Scooped flour can vary by more than 20% cup to cup, which swamps a 2% salt figure entirely.
- Forgetting scaling loss. Dough left in the mixer, on the bench and on your hands is real. Add 1-3% to the target dough weight if you must hit an exact piece count.
- Mixing yeast types without converting. Instant, active dry and fresh yeast are not the same weight for the same activity.
- Ignoring the water inside milk, eggs and butter. An enriched dough at a nominal 50% water can behave like 60% once those liquids are counted.
- Rounding salt to the nearest gram on a small batch. On 300 g of flour, 6 g and 7 g of salt are 2.0% and 2.3% — a difference you can taste.
Where baker's percentage sits among the other formula tools
Baker's percentage is a scaling language, not a recipe. It tells you the ratios and lets you move between batch sizes; it says nothing about time, temperature or technique. Three companion calculations finish the job.
Hydration accounting handles the water hidden in non-water liquids and inside a levain. Once your formula has milk, eggs, butter or a starter in it, the number in the water field stops being the true hydration.
Dough temperature controls fermentation speed, and it is the variable most often left to chance. Two identical formulas mixed to 74°F and 80°F are different breads. The desired dough temperature calculator gives you the water temperature that lands your mix where you want it.
Piece scaling converts a dough weight into a product. For pizza that means dough balls and thickness factors, which the pizza dough ball calculator handles directly, including a waste allowance.
One limitation worth naming: this calculator assumes the percentages you enter are all measured against the same flour total, and that nothing evaporates. Bake loss — typically 10-15% of dough weight for a crusty hearth loaf — happens after this arithmetic ends. If you need a specific baked weight, divide it by (1 − bake loss) before entering a target dough weight here.
Key terms
- Baker's percentage
- A ratio system in which every ingredient is stated as a percentage of the total flour weight, and flour itself is 100%. Also called baker's math or formula percentage.
- Total formula percentage
- The sum of every percentage, flour included. Divided by 100 it gives the dough yield: the weight of dough produced per unit of flour.
- Hydration
- The water percentage. Strictly, all water in the formula divided by all flour in the formula, including the flour and water carried by a levain.
- Levain or preferment
- A portion of flour, water and leaven fermented ahead of the final mix. Entered here at its full weight as a percentage of the formula's flour.
- Scaling
- Weighing out ingredients, and separately, dividing bulk dough into pieces of a fixed weight. Scaling loss is the dough that never reaches a piece.
- Dough yield
- Total dough weight divided by flour weight. European bakeries often quote it as Teigausbeute, a number near 170 for a lean wheat dough.