Baker’s percentage expresses every ingredient as a percentage of the total flour weight, which is always set to 100%. For example, 75% hydration means the water weighs 75% of the flour weight. This system lets bakers scale recipes to any size while keeping ratios perfectly consistent, and is the standard way professional and home bakers communicate sourdough recipes worldwide.

Beginner sourdough bakers should start around 65-70% hydration, which produces a firmer, much easier-to-handle dough. Intermediate bakers often move to 75-80% for a more open crumb and chewier crust. Advanced bakers may push to 85% or higher for very open, artisan-style loaves with large irregular holes, though this requires more practice handling wet, slack dough.

A typical starter (levain) inoculation is 15-20% of the flour weight for an overnight bulk ferment at room temperature. Using less starter (5-10%) slows fermentation and develops more complex flavour, often used in combination with a longer cold proof in the fridge. Using more starter (25-30%) speeds up fermentation considerably, which is useful in cooler kitchens or when you need a same-day bake.

The standard sourdough salt percentage is 2% of the total flour weight. This is the sweet spot for flavour, crust development, and controlling fermentation speed, since salt slightly slows down yeast and bacterial activity. Some bakers go as low as 1.8% for a milder taste, or as high as 2.2% for a more pronounced salty flavour and a slightly slower, more controlled ferment.

Yes. A mature starter is typically 50% flour and 50% water (100% hydration), so when you add starter to your dough you are also adding both flour and water that must be accounted for in your overall hydration calculation. This calculator automatically factors the starter’s own flour and water content into the final dough hydration percentage, so the numbers you enter reflect the true, total dough composition.

To scale a recipe, decide on your desired total dough weight, then work backwards using baker’s percentages. If your recipe is 70% hydration, 20% starter, and 2% salt, the total percentage is 192% (100% flour + 70% water + 20% starter + 2% salt). Divide your target dough weight by 1.92 to get your flour weight, then calculate water, starter, and salt from there. This calculator does all of this automatically for you.

A starter (or mother culture) is the ongoing, perpetually maintained wild yeast and bacteria culture that you feed regularly to keep alive between bakes. A levain is a portion of that starter built up specifically for a single bake, sometimes using a different flour or hydration than your everyday maintenance starter. Many bakers keep a small, low-maintenance starter and build a larger levain the night before they plan to bake.

Flour absorption varies significantly between brands, protein content, freshness, and even ambient humidity in your kitchen. A calculated 75% hydration dough may feel notably firmer or wetter depending on your specific flour. Treat the calculator’s hydration percentage as a starting reference point, and adjust your water slightly based on how the dough actually feels and behaves during mixing — this is a normal and expected part of sourdough baking.