Dough Hydration Calculator
Works out what your dough is really hydrated to, counting the flour and water inside a preferment and the water hidden in milk, eggs, butter and honey — which is why a dough recorded at 65% can genuinely be 71%.
Dough Hydration Calculator
Results recalculate instantly on every keystroke. Nothing you type is transmitted.
What this result does not account for
- Water contents are standard averages; egg size, butterfat percentage and honey variety all shift them.
- Preferment hydration is taken as declared and assumes it was fed at that ratio.
- Flour absorption capacity is not modelled — the same percentage behaves differently in bread flour, soft flour and whole wheat.
- Hydration alone does not determine handling; mixing, fermentation time, temperature and salt all matter independently.
- Solids from milk, egg and honey are excluded from both sides, which is correct for hydration but means the figure is not a moisture balance.
In short: Hydration is water divided by flour, but both numbers are usually wrong. A preferment carries flour and water, so 500 g of flour with 325 g of water plus 200 g of 100% starter is not 65% — it is 70.8%. And milk is 87% water, eggs 75%, butter 16%: an enriched dough recorded at 40% can truly be 76.5%. That gap is why a dough behaves nothing like its number says it should.
Formula
hydration % = total water ÷ total flour × 100
preferment flour = preferment weight ÷ (1 + hydration ÷ 100) · water = weight − flour
hidden water = milk×0.87 + egg×0.75 + butter×0.16 + honey×0.17
1 percentage point of hydration = flour weight × 0.01 in water
[('100%', "Flour, always, in baker's math. Every other ingredient is a percentage of it."), ('87% / 75%', 'Water content of milk and of whole egg — the two enrichments that most distort a hydration figure.'), ('0%', 'Oil. The only common wet ingredient that adds no water at all.'), ('50%', 'A 100%-hydration starter is half flour by weight, and that flour belongs in the denominator.')]
Worked Example
- Split the preferment. Divide its weight by one plus its hydration to get its flour; the remainder is its water. Both go into the totals.
- Convert the enrichments to water. Multiply each by its water content. Milk 0.87, egg 0.75, butter 0.16, honey 0.17, oil zero.
- Add up both sides. All flour from every source; all water from every source.
- Divide and read the band. Water over flour, times a hundred. The handling band tells you what to expect at the bench.
- Adjust in small steps. One percentage point is flour weight divided by a hundred, in water. Rest the dough before judging.
Five hundred grams of flour with 325 g of water is a straightforward 65% dough. Add 200 g of a 100% hydration starter and the recipe still says 65% — but the starter brought 100 g of flour and 100 g of water, so the dough is really 425 over 600, which is 70.8%. Nearly six percentage points appeared from nowhere, and at that end of the range six points is the difference between a dough that holds a shape and one that flows off the peel.
Strengths & Limits Of This Model
Where this engine is strong
- Counts the flour inside a preferment, which is the single most common error in hydration arithmetic.
- Converts enrichments to their actual water content instead of ignoring them or treating them as water.
- Shows the apparent figure alongside the true one so the size of the gap is visible.
- Translates the percentage into what the dough will feel like at the bench.
Where it stops
- Cannot tell you what hydration your particular flour wants, only what you have.
- Composition figures are averages and real ingredients vary.
- Does not model absorption over time, which matters most for whole grain flours.
Practical Use Cases
Comparing a sourdough recipe with a straight-dough one
The starter has to be split into flour and water before the two formulas are on the same footing.
Understanding why an enriched dough behaves wetter than its numbers
A brioche listing 40% hydration is often above 75% once the milk, eggs and butter are counted.
Converting a favourite recipe into baker's percentages
Once the true hydration is known, the formula scales to any batch size without re-deriving anything.
Diagnosing a dough that will not hold its shape
The stated hydration and the real hydration are frequently several points apart, and the dough obeys the real one.
Methodology & Editorial Standards
Hydration is computed as total water divided by total flour, expressed as a percentage, following the baker's-percentage convention in which flour is always the 100% reference. The distinguishing step is that both totals are assembled from every source rather than from the ingredients a recipe happens to label as flour and water. A preferment is decomposed using its declared hydration: flour equals the preferment weight divided by one plus the hydration fraction, and water is the remainder, so a 200 g starter at 100% resolves to 100 g of each. Enrichments are converted to water using standard composition figures — milk 87%, buttermilk 90%, yogurt 85%, whole egg 75%, honey 17%, butter 16% and oil 0% — and only the water fraction enters the numerator, with the solids deliberately excluded from both sides since they are neither flour nor water. Handling bands are the conventional ranges used in bread practice. The salt reference of 1.8–2.2% of flour weight is the standard range. Flour absorption is explicitly not modelled: the tool reports the ratio present, not the ratio a given flour will comfortably carry.
Computation runs in IEEE-754 double precision at full internal precision; rounding to two decimal places occurs strictly at the display layer, so no cumulative drift enters the result. All monetary outputs use accounting presentation — grouped thousands, two decimals, negatives in parentheses — so figures can be transcribed directly into a model or working paper. Division-by-zero and out-of-domain inputs return an em-dash rather than a misleading number.
This engine was reconciled against an independent reference implementation and hand-verified for the worked example above before release. Our full five-stage review process is published on the About Us page.
Disclaimer. This calculator is provided for informational and modelling purposes only and does not constitute financial, tax, legal, medical, or engineering advice. Verify all figures with a qualified professional before acting on them.
Dough Hydration Calculator — 20 Expert FAQs
20 analyst-written answers to the questions practitioners actually ask — optimised for voice and answer-engine retrieval.
How do I calculate dough hydration?
Divide the total water by the total flour and multiply by 100. The word ‘total’ is doing the work: it includes the flour and water inside any preferment, and the water carried by milk, eggs, butter and honey. Five hundred grams of flour and 325 g of water is 65%. Add a 200 g starter at 100% hydration and it becomes 70.8%, because the starter contributed 100 g of each.
Does sourdough starter count towards hydration?
Yes, on both sides of the fraction. A starter is pre-mixed flour and water, not a wet ingredient. At 100% hydration it is half flour and half water by weight, so 200 g adds 100 g to the flour total and 100 g to the water total. Leaving it out understates both, and the resulting hydration figure can be several percentage points off in either direction depending on whether the starter is wetter or stiffer than the dough.
Does milk count as water in dough hydration?
Mostly. Milk is about 87% water by weight, so 100 g of milk contributes 87 g of water and 13 g of solids. Buttermilk is around 90%, yogurt 85%. Treating milk as if it were water overstates hydration slightly; ignoring it entirely understates hydration a great deal. The same logic applies to eggs at 75% and, to a much smaller degree, butter at 16%.
What hydration should my bread dough be?
Between 58% and 65% for most everyday breads, which is firm, tacky and forgiving. Below 58% is stiff and gives a tight crumb; 65% to 70% is soft and sticky with a more open crumb; above 70% is genuinely slack and needs wet hands, a bench scraper and stretch-and-fold rather than kneading. Ciabatta and focaccia run 75% to 85% and rely on the pan or the peel for shape.
Why does my 70% hydration dough feel different from someone else's?
Because absorption varies by flour. Strong bread flour at 12.7% protein takes up considerably more water than a soft flour at 9%, and whole wheat takes more again — and keeps taking it for hours as the bran hydrates. The percentage is only comparable within a flour type. It is also affected by how dry your flour is, which changes with storage and with the season.
Is oil part of hydration?
No. Oil is 0% water, so it contributes nothing to hydration even though it is unmistakably wet. It does change handling — it coats gluten strands, softens the crumb and makes the dough feel more extensible — but it belongs in the formula as a separate percentage, not in the water total. Butter is the awkward middle case at about 16% water and 80 to 82% fat.
How do I raise or lower hydration?
One percentage point equals the flour weight divided by a hundred, in water. For 600 g of total flour that is 6 g per point. To go drier you can add flour instead, but note it moves the figure twice — it raises the denominator as well — so you need less than you might expect. Always rest the dough twenty minutes before judging, because flour keeps absorbing.
What is baker's percentage?
A convention in which flour is always 100% and every other ingredient is expressed as a percentage of the flour weight. Water becomes hydration, and salt, yeast, fat and sugar follow the same way. Because everything is a ratio against a single reference, the formula scales to any batch size exactly. It also means the percentages add up to well over 100, which surprises people the first time they see it.
Does higher hydration always mean a more open crumb?
It helps, but it is not sufficient on its own. An open crumb also needs adequate gluten development, sufficient fermentation, gentle shaping that does not degas the dough, and enough oven heat for good spring. Simply adding water to a dough that is under-fermented or weakly developed produces a flat, dense, gummy loaf rather than an airy one.
Why is my whole wheat dough stiffer than the percentage suggests?
Bran and germ absorb a great deal of water, and they do it slowly, so a whole wheat dough that feels correct at mixing can feel dry an hour later. Whole wheat generally needs five to ten percentage points more hydration than white flour for equivalent handling, and it benefits particularly from an autolyse, which gives the bran time to drink before you judge the consistency.
Is this dough hydration calculator free to use?
Yes. It is free, requires no account, and has no usage limits. ApexConverter is funded by contextual advertising, never by selling user data.
Is my data sent to a server?
No. The engine runs as Vanilla JavaScript inside your browser under our Zero-Server Client-Side Execution model. Your figures are computed locally and are never transmitted, logged, or stored.
How accurate is this calculator?
It applies the standard closed-form formula in IEEE-754 double precision, rounding only at the display layer. The engine is reconciled against an independent reference implementation before release.
Does it work on mobile?
Yes. The interface is mobile-first with numeric keypad hints and is tested down to a 320-pixel viewport with no horizontal scrolling.
Can I use it offline?
Largely, yes. Because computation is client-side, the page continues to calculate without a network connection once it has loaded.
Which currency does it use?
Amounts display in US$ accounting format, but the underlying mathematics is currency-agnostic. The result is identical in any currency, so simply read the figures in your own.
Why does a result show an em-dash?
An em-dash indicates the calculation is not defined for the inputs given — typically a division by zero or a value outside the valid domain. We show a dash rather than a misleading number.
How do I report an error?
Email apexconverter.praxiscalc@gmail.com with the tool URL, your exact inputs, the output received and the output you expected. Verified mathematical errors are patched within 72 hours.
Where can I find related dough hydration calculator tools? (1)
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Where can I find related dough hydration calculator tools? (2)
Use the Related Engines panel on this page, or open the category hub for all 50 tools.