The baker's percentage calculator above works the way a professional bread formula works: flour is always 100 percent, and every other ingredient is written as a percentage of the flour weight. Once a recipe is expressed that way it stops being a fixed list of quantities and becomes a formula you can scale to any size. Two loaves or two hundred, a partial bag of flour or an exact target dough weight — the ratios stay identical and only the absolute grams change.
Arb Digital builds free calculators for the moments where the arithmetic is the only thing standing between you and getting on with the job. Baker's percentage is a small piece of maths that home bakers hit constantly and usually solve with a scribbled cross-multiplication. This tool does it in both directions, shows the full ingredient list at your chosen scale, and displays each ingredient as a share of the finished dough so you can see immediately what kind of bread the numbers describe.
What This Baker's Percentage Calculator Does
Enter your percentages once — hydration, salt, yeast or starter, fat and sugar — then anchor the formula in whichever way suits the job. Tell it how many loaves you want and how heavy each should be, give it a total dough weight, or give it the flour you actually have in the cupboard. It computes every ingredient in grams, the total dough weight, and the percentage of the finished dough that each ingredient represents.
The handling loss allowance is the feature bakers ask for most. A formula that produces exactly 2,700 grams of dough will not give you three 900 gram loaves, because dough is left behind on the bowl, on the bench, on the scraper and on your hands. Adding two or three percent scales the whole formula up slightly so the loaves you actually shape come out at the weight you intended.
Two things this page deliberately does not do. It does not convert to cups, because flour measured by volume varies by a large margin depending on how it was scooped and settled, which is the reason bread formulas are written by weight in the first place; our cooking measurement converter handles volume conversions when a recipe leaves you no choice. And it does not compute a pizza dough by diameter — that is a different anchor with its own conventions, handled by our pizza dough calculator.
How to Use It
- Pick your starting anchor. Loaves and loaf weight is the usual home-baking route. Total dough weight suits a tin or banneton of known capacity. Flour weight suits using up what is left in the bag.
- Set hydration. This is water as a percentage of flour. Around 60 to 65 is a firm sandwich dough, 70 to 75 an open crumb, and above 80 a very slack dough that needs experience to handle.
- Set salt and leavening. Salt is conventionally around 2 percent of flour. Yeast varies enormously with the fermentation schedule, which is a topic in its own right below.
- Add fat and sugar if the bread has them. Leave them at zero for a lean dough. Enriched breads carry meaningful amounts of both, and both change how the dough behaves.
- Add a handling loss allowance of two to three percent if you need the finished loaves to hit an exact weight.
The Formula and How It Is Calculated
Every ingredient is a fixed multiple of the flour weight:
Ingredient weight = flour weight × (its percentage ÷ 100)
The total dough weight is the flour plus everything else, which means it is the flour multiplied by the sum of all the percentages including the flour's own 100:
Total dough = flour × (100 + water% + salt% + yeast% + fat% + sugar%) ÷ 100
Running that in reverse is what lets you scale to a target. Rearranged, flour = total dough × 100 ÷ sum of percentages.
Take the example loaded above: three loaves at 900 grams each is 2,700 grams of dough, at 70 percent hydration, 2 percent salt and 1 percent yeast. The percentages sum to 100 + 70 + 2 + 1 = 173. Flour is therefore 2,700 × 100 ÷ 173 = 1,560.7 grams. Water is 70 percent of that, or 1,092.5 grams. Salt is 31.2 grams and yeast is 15.6 grams. Add them up and you get 2,700 grams exactly, which is the check that the reverse calculation is right.
Notice what the percentages do not tell you: 70 percent hydration is 40.5 percent of the dough by weight, not 70 percent. Bakers use flour as the base precisely because it makes formulas comparable — a 70 percent dough is a 70 percent dough whether it contains oil and sugar or not, whereas water-as-a-share-of-total would shift every time another ingredient was added.
Why Hydration Numbers Do Not Transfer Between Flours
Two bakers can follow the same 75 percent formula and end up with completely different doughs, because the number describes how much water you added, not how much water the flour absorbed. Absorption depends chiefly on protein content and on how finely the flour is milled. A strong bread flour with high protein takes up considerably more water than a soft plain flour before it becomes slack, and wholemeal takes more still because the bran fragments hold water that never reaches the gluten network.
This is why an internet formula at a specific hydration so often fails on the first attempt. The honest way to use a published percentage is as a starting point, then adjust in small steps and record what your flour actually wanted. Two or three percent either way is a large visible difference in dough handling and a rounding error in the maths.
Wholemeal deserves a specific note. The bran absorbs water slowly, so a wholemeal dough that feels correct at mixing can feel dry twenty minutes later. Bakers deal with this by resting the flour and water together before adding salt and yeast, which gives absorption time to finish before any judgement is made about the dough. If you convert a white formula to wholemeal at the same hydration, expect it to feel tight and expect to need more water rather than less.
Salt and Yeast Are Not Interchangeable Dials
Salt sits at roughly 2 percent of flour in most bread formulas, and the range that works at all is narrow. Below about 1.5 percent bread tastes noticeably flat and the dough slackens, because salt tightens the gluten structure as well as seasoning. Above about 2.5 percent the bread tastes salty and fermentation slows measurably, since salt restrains yeast activity. A formula that seems to under-salt is often written for a dough where salt arrives from another source, such as a salted butter or a brine.
Yeast is the opposite: its percentage is almost meaningless without the time and temperature that go with it. The same loaf can be made with 2 percent fresh yeast in two hours or 0.2 percent over a long cool overnight rise, and the slow version will taste better because fermentation flavour needs time to develop. When you copy a yeast percentage from one recipe into another schedule, you are not copying a fixed quantity — you are copying half of a pair. Halve the yeast and you roughly double the time at the same temperature, which is a rough guide rather than a law.
Sourdough starter is entered in the same field but behaves differently again, because it brings its own flour and water into the dough. A formula that uses 20 percent starter at 100 percent hydration is carrying 10 percent extra flour and 10 percent extra water that the simple percentages here do not separate out. For casual use this is a small distortion; for precise work, subtract the starter's flour and water from the main quantities.
Scaling Up Is Not Just Multiplication
The arithmetic scales perfectly. The physics does not, and that is where a doubled recipe goes wrong. A larger batch of dough holds heat, so a big mix ferments faster in its own centre than a small one does — final dough temperature matters more as batch size grows, and experienced bakers adjust water temperature to hit a target rather than using tap water and hoping.
Mixing changes too. A domestic mixer that develops one kilogram of dough well may simply push a three kilogram batch around the bowl without developing it, and hand-mixing a large slack dough is genuinely difficult. Scaling down has its own problem: at very small quantities, weighing 0.4 grams of yeast accurately requires a scale most kitchens do not have, and the usual workaround is to make a larger batch of dough and freeze part of it after shaping.
Baking loss is the last thing scaling does not capture. A loaf loses moisture in the oven, typically in the region of a tenth of its weight for a standard tin loaf and more for a small free-form loaf with a large crust. If you need a specific baked weight rather than a specific dough weight, you must add that loss on top of the handling allowance. Our percentage calculator is quick for that adjustment, and our ratio calculator is useful when you want to express a formula as a simple ratio rather than a percentage set.
Weighing, Accuracy and Where Grams Actually Matter
Not every ingredient needs the same precision. Flour and water tolerate a gram or two either way without any visible consequence. Salt and yeast do not, because they are present in small quantities and a one gram error on a four gram yeast measurement is a 25 percent change to your fermentation rate. A scale that reads to 0.1 grams for the small ingredients is the single most useful upgrade for anyone baking from percentages.
Weight is also the only sound basis for water. One millilitre of water weighs almost exactly one gram at kitchen temperatures, so a scale replaces a jug with no loss of accuracy and considerably less washing up. The formal definitions behind these units are maintained by the NIST Office of Weights and Measures, and composition data for flours and other ingredients is published in USDA FoodData Central if you want to look up protein content rather than trust a packet claim. If you are working in imperial units, our grams to ounces converter and weight converter handle that step.
One safety point that belongs on any page about dough: raw flour is a raw agricultural product and has been linked to foodborne illness outbreaks, so tasting raw dough or batter is not risk free. The FDA's guidance on handling flour safely sets out the reasoning and the handling steps.
Arb Digital publishes hundreds of free calculators across food, finance, health and maths — no sign-up, no limits. If something you need is missing, tell us and we will look at building it.
Browse All Free Tools Suggest a ToolCommon Mistakes to Avoid
- Taking percentages of the total dough weight — they are percentages of flour. Reading 70 percent hydration as 70 percent of the dough gives a soup rather than a bread.
- Copying a yeast percentage without its schedule — the same figure means a two-hour rise in a warm kitchen and a stalled dough in a cold one. Yeast and time are one setting, not two.
- Assuming a hydration transfers between flours — protein content and milling change absorption. Treat a published number as a starting point and adjust to the dough in front of you.
- Forgetting the flour and water inside a sourdough starter — a starter contributes both, so a formula with a large preferment is not quite at the hydration the headline number suggests.
- Scaling to an exact dough weight with no loss allowance — dough left on the bowl and bench means the last loaf is always the light one.
Related Free Tools From Arb Digital
Work the same ratio logic in dough-ball form with the pizza dough calculator, convert a stubborn volume-based recipe with the cooking measurement converter, and switch units with the weight converter or the grams to ounces converter. For quick proportional adjustments the percentage calculator and the ratio calculator both help, and the free online tools hub lists everything else.
Frequently Asked Questions
It is a way of writing a bread formula in which the flour is always 100 percent and every other ingredient is expressed as a percentage of that flour weight. It makes formulas directly comparable and lets you scale a recipe to any batch size by changing only the flour figure.
Because flour is the base rather than the total. Flour is 100 percent by definition, so a dough with 70 percent water, 2 percent salt and 1 percent yeast sums to 173 percent. The total dough weight is the flour weight multiplied by 1.73.
Divide the target dough weight by the sum of all the percentages, then multiply by 100. For 2,700 grams of dough at 70 percent hydration, 2 percent salt and 1 percent yeast, the sum is 173, so flour is 2,700 times 100 divided by 173, which is about 1,561 grams.
It is the water weight as a share of the flour weight, not of the dough. A 75 percent dough contains 750 grams of water for every kilogram of flour. As a share of the finished dough that same water is closer to 42 percent, which is why the two figures should never be confused.
Most lean bread formulas sit at roughly 2 percent of flour weight. Below about 1.5 percent the bread tastes flat and the dough slackens, and above about 2.5 percent the flavour turns salty and fermentation slows, because salt restrains yeast activity as well as seasoning the loaf.
Yes, by entering your starter in the yeast field as a percentage of flour. Be aware that a starter carries its own flour and water into the dough, so a formula using a large preferment is slightly wetter and slightly higher in flour than the headline percentages suggest.
Dough is left behind on the bowl, the scraper, the bench and your hands, so a formula scaled to exactly the dough you need always comes up short. Adding two or three percent scales the whole formula up a little so the shaped loaves hit the weight you intended.
Because flour measured by volume varies substantially depending on whether it was scooped, spooned or settled, and a difference of that size changes hydration enough to change the bread. Water is the easy case, since one millilitre weighs almost exactly one gram, so a scale handles both ingredients accurately.
This calculator is provided for general education and reference. It describes how bread formulas are scaled and is not food safety guidance; raw flour and raw dough should not be tasted, and you should follow the food safety advice issued by your national authority.
