How to Calculate Baker’s Percentages for Bread — and Scale Any Dough Formula

Baker’s math confuses people for one reason: the numbers don’t add up to 100. A perfectly ordinary bread formula can read flour 100%, water 70%, salt 2%, and yeast 1% — and total 173%. Nothing is wrong. That total is a feature of the system, not an error in your arithmetic.

Baker’s percentages describe a dough by its proportions instead of its quantities. Once you can write a formula that way, you can scale it to any batch size, compare two recipes side by side, and adjust hydration deliberately rather than by guesswork. What follows is the full method: converting a recipe you already use, scaling it up or down, and handling the parts that trip people up — multiple flours, sourdough starter, and enriched doughs.

What Baker’s Percentage Is and Why It Makes Scaling Bread Simple

Baker’s percentage — also called baker’s math or formula percentage — expresses every ingredient in a dough as a proportion of the flour. Flour is the reference point; everything else is measured against it.

That single convention delivers two practical benefits.

Scaling without rewriting. A formula that reads flour 100%, water 72%, salt 2%, yeast 1.2% works at 500 g of flour or 50 kg. You multiply; you don’t re-derive. A bakery moving from 20 loaves to 200 changes one number, and so does a home baker moving from one loaf to three.

Comparison. Two recipes with different batch sizes are hard to judge on sight. Written as percentages, the differences are obvious: one dough is 68% hydration, the other is 80%. You can see at a glance which is wetter, which is saltier, and which will ferment faster.

The One Rule to Remember: Flour Is Always 100%

Two rules, really, and they’re inseparable. Total flour is always 100%, and every other ingredient’s percentage is calculated against total flour weight — never against total dough weight.

A dough with 2% salt contains 2 g of salt for every 100 g of flour, not 2 g per 100 g of finished dough. That distinction matters the moment you scale, because salt scales with flour while flour is only part of the dough.

The 100 g base is what makes the system readable. When flour sits at 100%, each percentage translates directly into grams per 100 g of flour. A 1.8% salt dough is 1.8 g of salt per 100 g of flour. You can picture the dough from the numbers alone.

The Baker’s Percentage Formula: A Simple Calculation

The arithmetic is one division:

baker’s percentage = (ingredient weight ÷ total flour weight) × 100%.

If a dough uses 500 g of flour and 350 g of water, the water percentage is 350 ÷ 500 × 100, or 70%. Divide each ingredient’s weight by the total flour weight and multiply by 100, and you have that ingredient’s percentage. That relationship is the whole system; everything else in this article is an application of it.

“Total flour weight” is doing real work in that sentence. When a dough contains one flour, it’s the weight of that flour. When it contains three, it’s the sum of all three.

Step-by-Step: Converting a Grams-Based Recipe to Baker’s Percentages

Take a straightforward yeasted dough:

Step 1 — Add up the flour. Only flour counts. Here it’s 500 g.

Step 2 — Divide and multiply. For each remaining ingredient: weight ÷ 500 × 100.

• Water: 350 ÷ 500 × 100 = 70%
• Salt: 10 ÷ 500 × 100 = 2%
• Yeast: 5 ÷ 500 × 100 = 1%

Step 3 — Write the formula. Flour 100%, water 70%, salt 2%, instant yeast 1%.

Step 4 — Check your work. Sum the percentages: 100 + 70 + 2 + 1 = 173%. Multiply that by the flour weight and divide by 100: 500 × 1.73 = 865 g, which is exactly the original dough weight (500 + 350 + 10 + 5). If those two figures don’t match, you divided by the wrong base.

Converting Percentages Back to Grams: Scaling to Any Batch Size

There are three situations, and they call for slightly different moves.

Starting from a flour weight: multiply. A formula of flour 100%, water 80%, levain 20%, salt 2% at 1,500 g of flour becomes 1,200 g water, 300 g levain, and 30 g salt. Each percentage is simply multiplied by the flour weight.

Starting from a dough weight: work backwards. Add the percentages, then divide the desired dough weight by that sum of percentages, and multiply each percentage by the result. Using flour 100%, water 70%, fresh yeast 1%, salt 2% — a total of 173% — a 2,000 g batch gives 2,000 ÷ 173 = 11.56, so 1,156 g flour, 809 g water, 11.6 g yeast, and 23.1 g salt.

Scaling an existing recipe: use a conversion factor. Divide desired flour weight by original flour weight. Scaling the recipe above (500 g flour) to 750 g gives a factor of 1.5, so 750 g flour, 525 g water, 15 g salt, 7.5 g yeast.

Multiple loaves of different sizes in one batch. Add up the target dough weight for every loaf. Then use the dough-weight method: divide that total by the formula’s total percentage to get total flour weight, and multiply every ingredient percentage by that flour weight. For example, one 900 g loaf plus two 500 g loaves is 1,900 g of dough. From a 173% formula, 1,900 ÷ 173 = 10.98, and 10.98 × 100 = 1,098 g total flour. If you prefer, scale to the total flour weight first, mix one batch, then divide the finished dough by weight into the sizes you need. Weigh the pieces rather than estimating; different-sized loaves will also need different bake times.

The flour-weight route is simpler and preferable when you’re adjusting hydration or comparing formulas. The dough-weight route is the one to use when a pan, a loaf count, or an order dictates the batch size.

Hydration: The Percentage That Determines Dough Consistency

Hydration is just the water percentage: water weight ÷ total flour weight × 100. In the example dough, 350 ÷ 500 × 100 = 70%.

Widely used ranges you’ll see across many bread styles:

Treat these as context, not targets. The same 75% feels slack with one bread flour and manageable with another. Whole wheat, rye, and freshly milled flours absorb more water, so a whole-grain dough often needs a higher percentage to reach the same handling consistency. Adjust based on how the dough feels and develops rather than on matching a number on a page.

Salt, Yeast, Sugar, and Fat: Typical Percentages and How to Adjust

Salt sits at 2% by near-universal default. Below roughly 1.5%, dough tastes flat and fermentation moves faster; above roughly 2.5%, salt noticeably slows yeast activity.

Yeast has the widest practical range because time is the other variable. A straight dough mixed and baked the same day might use 1–2% instant yeast. A cold-fermented dough can use 0.3–0.5% and get there slowly, building more flavor along the way. This is a decision about your schedule as much as your formula.

Sugar and fat are structural in enriched doughs, not just flavor. Sugar at 8% or more promotes browning and tenderizes the crumb; fat coats gluten proteins and shortens strands. Both slow fermentation, which is why enriched doughs generally carry more yeast than lean ones — the yeast has more to work through.

For converting between fresh, active dry, and instant yeast, follow your manufacturer’s guidance. Conversion ratios vary by product and are not interchangeable across brands.

Multiple Flours: How to Keep One Total Flour Weight as 100%

The rule is simple: the combined weight of all flours equals 100%.

A dough with 300 g bread flour and 200 g whole wheat flour has 500 g of total flour. Bread flour is 300 ÷ 500 × 100 = 60%; whole wheat is 40%. You do not write bread flour as 100% and whole wheat as a separate 100%.

For an illustrative example, a sourdough formula might list 800 g bread flour and 200 g whole wheat flour — 80% and 20% on a combined flour weight — with water at 76% and salt at 1.9%. Starter is often listed separately, and its percentage varies widely by formula and schedule; if you count the starter’s flour inside the total, the base-flour percentages shift. The key point is that the percentages are relative to the sum of both flours, which is why the bread flour reads 80% rather than 100%.

This matters most when you swap flours. Changing the whole wheat from 20% to 40% while holding hydration steady will change the dough’s feel, because you’ve changed the blend that the water percentage is measured against.

Preferments and Sourdough Starter: Accounting for Flour and Water

Preferments are where baker’s math earns its keep — and where most home bakers lose the thread. A poolish, biga, levain, or sourdough starter isn’t a single ingredient. It’s flour and water in a known ratio.

You have two honest ways to write it.

List the preferment as its own line, with the base flour at 100%. Flour 100%, water 67%, starter 20%, salt 2%. This is easy to read and easy to mix, and it scales correctly as written. But the stated hydration is nominal: if the starter is 100% hydration, it brings flour and water of its own, and true hydration runs higher than 67%.

Use the total-flour method when accuracy matters. Include the preferment’s flour inside the 100% and its water inside the water percentage, then subtract both from what you weigh at mixing time.

Worked example: 500 g total flour, 70% hydration, starter at 20% and 100% hydration, salt at 2%.

• Starter: 20% × 500 g = 100 g, which is 50 g flour plus 50 g water
• Flour weighed into the main dough: 500 − 50 = 450 g (90%)
• Total water: 70% × 500 = 350 g; 50 g already arrives in the starter, so weigh 300 g (60%)
• Salt: 2% × 500 = 10 g

The formula now reads: main dough flour 90%, water 60%, starter 20%, salt 2%. Sum: 172%, and 500 × 1.72 = 860 g of dough. True hydration is 350 ÷ 500 = 70%, which is how the dough will actually behave.

Whichever format you choose, label it. “Flour 100%” means two different things depending on whether the starter’s flour sits inside that number, and a formula you can’t read six months later is a formula you’ll have to rebuild.

Enriched Doughs: How to Treat Eggs, Milk, Butter, Honey, and Add-Ins

Every enrichment gets identical treatment: divide by total flour weight. Nothing is exempt.

Sum: 191.6%, so the dough weighs about 958 g.

Two things are worth noticing. The water percentage looks low because so much liquid arrives in the eggs and milk. And those liquids contain water, so effective hydration is considerably higher than 30%. Whole egg is roughly three-quarters water by weight, milk around 87%, and butter roughly 16–18%, though exact figures vary by product. That puts this dough’s effective hydration near 61% — about what you’d expect for a soft enriched dough. Fat also changes how the dough handles, so hydration alone won’t predict behavior here.

Honey and syrups carry water too. If you’re tracking hydration closely, count them rather than treating them as dry ingredients.

Total Formula Percentage and Dough Yield: Why Your Numbers Exceed 100%

Total formula percentage is the sum of every ingredient percentage. Because flour alone is 100% and every other ingredient adds to it, the total always exceeds 100% unless the dough is flour and nothing else.

That total isn’t a percentage of anything — it’s a shortcut to dough weight. Total dough weight = total flour weight × (total formula percentage ÷ 100). The 173% formula on 500 g of flour yields 865 g of dough. Nothing is missing; every gram is accounted for.

This is the most common source of confusion in baker’s math. Percentages on a nutrition label sum to 100 because they describe composition. Percentages in a bread formula don’t, because they describe a ratio to flour.

Baker’s Percentage vs. True Percentage

True percentage — sometimes called percentage of total — treats the total dough weight as 100% and expresses each ingredient’s share of it. It’s how a label works. Baker’s percentage treats flour as 100%. The same dough, two views:

True percentage tells you what the dough is made of. Baker’s percentage tells you how to build it and how to change it. Want to raise hydration? Baker’s percentage gives you the number directly — water moves from 70% to 75%, full stop. In true percentage, you’d have to recalculate every other ingredient to hold the flour constant, which is precisely the problem baker’s math solves.

Common Mistakes and How to Avoid Them

Treating each flour as 100%. In a multi-flour dough, only the combined weight is 100%.

Dividing by total dough weight. The denominator is always total flour weight.

Forgetting the preferment’s flour. If you want true hydration, the flour and water inside your starter or levain count.

Expecting percentages to total 100%. They won’t. A total above 100% is normal and expected.

Adding percentages to get dough weight. Convert to grams first, then add. Percentages produce a ratio, not a weight.

Rounding too early. Carry full precision until the final step; see the rounding note in Rounding, Precision, and Practical Measurement.

Assuming hydration behaves the same across flours. It doesn’t. Whole-grain and rye flours absorb more water than white flour at the same percentage.

Ignoring water in eggs, milk, and butter. In enriched doughs, these carry most of the water in the formula.

Rounding, Precision, and Practical Measurement

Percentages: one decimal place is plenty, and whole numbers are usually sufficient. Salt at 2% versus 1.95% is not a meaningful distinction in a home kitchen.

Grams: carry full precision through the calculation, then round once at the end. For a 500 g flour batch, rounding a percentage to one decimal shifts an ingredient by half a gram — irrelevant. For a 10 kg batch, the same rounding moves 10 g, which is still small but worth being deliberate about.

Equipment: a scale reading to 1 g handles flour, water, and salt comfortably. For yeast and salt in small batches, a 0.1 g resolution removes guesswork. Weigh water as well as flour — volume measurement of flour is the largest single source of error in home baking, and the amount in a cup varies substantially depending on how it’s filled.

Worked Examples

A straight dough, converted and scaled

Original: 500 g bread flour, 350 g water, 10 g salt, 5 g instant yeast. Formula: 100% / 70% / 2% / 1%, total 173%. Target: 900 g of dough. Divide 900 by 173 = 5.2023. Flour 520.2 g, water 364.2 g, salt 10.4 g, yeast 5.2 g. Total: 900 g.

A sourdough formula with a levain

Target: 1,000 g total flour, 75% hydration, levain at 20% and 100% hydration, salt at 2%.

Levain: 200 g (100 g flour plus 100 g water). Flour into the main dough: 900 g. Total water: 750 g, minus 100 g from the levain, so 650 g. Salt: 20 g.

Formula: main flour 90%, water 65%, levain 20%, salt 2% — total 177%. Dough weight = 1,000 × 1.77 = 1,770 g. True hydration = 750 ÷ 1,000 = 75%.

An enriched dough

Using the table above (191.6% total, 958 g from 500 g flour): to make 1,200 g of dough, divide 1,200 by 191.6 = 6.263. That gives 626.3 g flour, 187.9 g water, 125.3 g egg, 100.2 g milk, 75.2 g butter, 62.6 g sugar, 12.5 g salt, and 10.0 g yeast — which sums to 1,200 g.

Choosing Your Tool: Manual Math, Spreadsheet, or Baker’s Percentage Calculator

Manual math. Manual math teaches you the structure of a formula, and structure is what you need when something goes wrong mid-mix. Work the arithmetic by hand for a month and you’ll stop needing to look up the method.

A spreadsheet. A spreadsheet earns its place once you bake the same formulas repeatedly. One column of percentages, one input cell for total flour weight, and the grams recalculate instantly. It also gives you somewhere to store variations side by side — 70% versus 75% versus 80% hydration of the same bread.

A dedicated baker’s percentage calculator. Fastest for one-off conversions: a recipe you found online, or reversing a known dough weight into ingredient weights. It won’t explain the result, so use it to check your manual work rather than replace it.

Frequently Asked Questions

How do I calculate baker’s percentages from a recipe that uses cups?
Weigh the ingredients as written, then run the same calculation. Volume doesn’t convert reliably to percentages until it’s in grams, and flour volume is especially variable. Weigh what your cup of flour actually holds, then use that number as your baseline.

How do I scale a formula for a specific loaf weight or pan size?
Work backwards from dough weight. Divide the target dough weight by your total formula percentage, and you have the flour weight. For pan loaves, match dough weight to pan capacity — a practical starting point is filling the pan roughly half to two-thirds with dough, then adjusting based on the loaf you get.

Do I include nuts, seeds, or dried fruit in the calculation?
You can, but they don’t behave like dough ingredients. Most bakers list them separately as a percentage of total flour weight — 20% toasted walnuts, for instance — so they scale with the batch without distorting the hydration numbers.

Can I use baker’s percentages to write a dough I’ve never made?
Yes, and it’s their best use. Choose a target hydration for the style, set salt at 2%, pick a yeast or starter level that fits your timeline, and the formula writes itself. Expect to adjust hydration on the first bake, since flour absorption varies from brand to brand.

Why did my scaled batch come out different from the original?
Check three things: whether you scaled by flour weight or dough weight, whether a preferment’s flour and water were included in the original numbers, and whether rounding crept into intermediate steps. Most discrepancies trace back to one of those three.

Once you’ve converted a few of your own recipes, the arithmetic stops feeling like arithmetic. You start reading formulas the way you read a recipe’s ingredient list — and adjusting them the way you’d adjust seasoning.