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If recipes that talk about "78% hydration" or "20% starter" make your eyes glaze over, this is for you. Baker's percentages sound fancy, but the idea is simple: your flour is always 100%, and every other ingredient is just a percentage of that flour. Water, salt, starter, all of it gets measured against the flour.
This calculator does that math for you. Plug in your numbers and it will scale your recipe, work out your hydration, and show you every ingredient as a clean baker's percentage. Whether you want to size a loaf up for a crowd or just finally understand what those numbers mean, you can play with it until it clicks.
Baker's percentage is just a way to compare and scale recipes, no matter how much dough you are making. The one rule to remember: flour is always 100%. Everything else is measured relative to your total flour weight.
So if a recipe has 440g flour and 340g water, your hydration is 340 divided by 440, which is about 77%. Salt of 8g works out to roughly 1.8%. Once you see recipes this way, you can scale them up or down freely and they will still behave the same, because the ratios stay the same.
The quick formula, if you ever want to do it by hand: ingredient weight divided by total flour weight, times 100.
Enter your flour, water, starter, salt, and any extras, and the calculator turns each one into a percentage of your flour. Want to scale a recipe? Adjust your total and everything moves together so the dough feels familiar even at a new size.
One thing worth knowing: your starter counts too. A starter is part flour and part water, and both of those numbers fold into your totals. That is why adding more starter quietly bumps up your hydration unless you hold a little water back. This calculator keeps track of that for you so your real hydration does not sneak away from you.
Most calculators assume a 100% hydration starter, meaning equal parts flour and water. I often bake with a stiffer starter, more like 50 to 60% hydration, because it gives me more control and the stiffer ratio slows down the rise. That changes the math: a stiff starter carries more flour than water, so it folds into your totals differently than a 1:1 starter would.
This is why I let you set your starter hydration rather than assuming it. Tell the calculator how stiff your starter is and it will split the flour and water correctly, so your final hydration is the real number, not a guess. Small detail, big difference in how your dough actually behaves.
It is a way to express a recipe where flour is always 100% and every other ingredient is a percentage of that flour. So 70% hydration means water equal to 70% of your flour weight. It makes recipes easy to compare and easy to scale.
Divide your total water by your total flour and multiply by 100. Just remember to count the flour and water hiding inside your starter, since both go into your totals. This calculator does that part automatically.
Yes. Your starter brings its own flour and water to the party, so it shifts your real hydration. Add more starter and your dough gets a little wetter unless you pull back some water. That is exactly the kind of bookkeeping this tool handles for you.
A stiff starter (around 50 to 60% hydration) has more flour than water, so it folds into your totals differently than a standard 100% one. Set your starter hydration in the calculator and it will split the numbers correctly, so your final hydration is accurate.
