Baker's percentage calculator
A starter at 100% hydration is half flour and half water. Adding 100 g of it to 500 g of flour gives 550 g of flour and 50 g of water already in the dough, so a 70% hydration loaf needs 385 g of water total and only 335 g added. Ignoring the starter makes the dough noticeably wetter than the number says.
Baker’s percentages state every ingredient against the flour, which is always 100%. Water divided by flour times a hundred is the hydration: 700 g into 1000 g is 70%. A starter at 100% hydration is half flour and half water, so 100 g of it puts 50 g of each into the dough before you pour anything.
How to use the baker's percentage calculator
Baker’s percentages exist so a recipe scales without arithmetic. Flour is 100% by definition and every other ingredient is expressed against it, so a formula reading 100% flour, 70% water, 2% salt works identically for 500 g or 50 kg. You change one number. It also makes two recipes directly comparable in a way gram weights never are: 70% hydration means the same thing in any bakery in the world.
The part that trips people is the starter, and this is where most calculators are simply wrong. A sourdough starter is itself flour and water. At 100% hydration, equal parts of each. Adding 100 g of starter adds 50 g of flour and 50 g of water to the dough, so both the total flour and the total water change, and the water you actually pour in has to be reduced accordingly. Ignore it and a nominal 70% dough is really closer to 75%, which is the difference between a manageable dough and a puddle.
The percentages sum to more than 100 and that is correct, not an error; they are ratios to flour, not fractions of the whole. A typical loaf comes to about 172%.
Useful ranges: 55–60% is stiff bagel or pasta dough, 60–65% a sandwich loaf, 65–75% most artisan bread, 75–85% ciabatta and focaccia territory where the dough turns genuinely awkward to handle, and past 85% you are working with something closer to a batter. Salt is almost always 1.8–2.2%; below that bread tastes flat and fermentation runs fast, above it the yeast is inhibited.
Hydration on its own is the figure most people arrive looking for, and it is the simplest one here: water divided by flour, times a hundred. What moves the right number is the flour. Strong bread flour absorbs more than plain, and wholemeal more again because of the bran, so the same 70% handles quite differently across three bags. Eggs and oil are not counted as water in the basic figure; some bakers count the roughly 75% of an egg that is water, which is fine as long as you say which convention a formula uses.
Pizza is the same arithmetic with the oven as the hidden variable. A wood-fired oven at 450 °C bakes in ninety seconds, so a wetter dough steams and puffs before it can dry out and 58–62% is right; a domestic oven at 250 °C takes eight minutes and turns that dough into a cracker, which is what 65% and a baking steel are compensating for. Pizza also runs saltier than bread at 2.5–3%, dough balls are 200–250 g for a 12-inch base and around 280 g for a 14-inch, and a cold ferment of 24 to 72 hours does more for the flavour than any change to the formula.
What people use it for
- Scaling a bread formula from 500 g to 50 kg
- Checking the hydration of a dough you have already mixed
- Working out the water to add when a sourdough starter is in the mix
- Adapting a Neapolitan pizza dough to a domestic oven
- Converting a percentage recipe into grams
Questions
They are ratios to the flour, not fractions of the total. A typical loaf comes to about 172%.
Water divided by flour, times a hundred. 700 g of water on 1,000 g of flour is 70%.
A starter is flour and water. At 100% hydration, 100 g of it adds 50 g of each, so both totals change and less water gets poured in.
60–65% for a sandwich loaf, 70–75% for a rustic one, 80%+ for ciabatta, which needs wet-dough handling.
Yes. The percentages are relative to flour, so a very wet dough or a batter goes past it and nothing is wrong.
A great deal. Strong bread flour absorbs more than plain, and wholemeal more again because of the bran.
Not in the basic figure. Some bakers count the water in an egg, which is about 75% of it; say which convention your formula uses.
Almost always 1.8–2.2%. Below that the bread tastes flat and ferments fast; above it the yeast is inhibited.
58–62% for a very hot oven, around 65% for a domestic one. The extra water compensates for the missing heat.
200–250 g for a 12-inch base and about 280 g for a 14-inch. Neapolitan style runs 250–280 g.
Yes: two and a half to three percent of the flour weight against about two. The base is thin and carries strongly flavoured toppings, and the extra salt also slows fermentation, which suits a dough sitting in the fridge for two days.
For a very hot oven, yes: it browns properly at 450 °C. In a domestic oven bread flour often performs better.
Twenty-four to seventy-two hours in the fridge. The flavour improves markedly across that range.
Yes — enter 0% starter and add yeast separately, typically 0.5–1% of the flour weight.