Sourdough Dough Calculator

How to Use This Sourdough Calculator

Choose how many loaves and the flour per loaf, then set hydration and starter percentage. The calculator applies baker's percentages to total flour and returns exact grams of water, ripe starter, and salt, plus the total dough weight and per-loaf dough weight. Salt stays fixed at 2%; that is the professional standard and should not change.

Baker's Percentages and Formula

Baker's math makes flour the anchor: every ingredient is a fraction of flour weight, so scaling is one multiplication per ingredient. The 70/20/2 standard is the Tartine-style baseline used across artisan baking. Starter percentage controls fermentation speed more than flavor; hydration controls crumb openness and handling difficulty. Salt at 2% seasons fully without inhibiting the culture.

Worked Example

Two standard loaves at 70% hydration, 20% starter: total flour = 2 x 500 = 1000 g. Water = 1000 x 0.70 = 700 g. Starter = 200 g. Salt = 20 g. Total dough = 1920 g, or 960 g per loaf. Divide in half after bulk fermentation, shape two boules, and cold retard overnight. The calculator shows this exact breakdown.

Practical Tips for Better Sourdough

Use a kitchen scale; sourdough is unforgiving of volume measurements. Keep a consistent flour blend so you learn how your dough behaves. Track dough temperature during bulk; 78F dough ferments nearly twice as fast as 70F dough. Do the windowpane test before ending bulk: stretch a piece thin and look for light through it without tearing. Score cold dough straight from the fridge for the cleanest ear.

Dough Builder vs Starter Feeding

This calculator builds the bread dough: flour, water, starter, and salt for actual loaves. A starter feeding calculator answers a different question: how much flour and water to feed your culture to have ripe starter ready. Feed the starter first with the feeding calculator, then plug the ripe starter grams into this builder. One maintains the culture; the other bakes the bread.

Second worked example: weekend loaf at 75 percent hydration

One loaf: 500 grams of bread flour, 375 grams of water, 100 grams of ripe starter (20 percent), and 10 grams of salt (2 percent). Mix flour and water, rest 1 hour. Add starter and salt, then 4 sets of stretch-and-folds over 2 hours. Bulk ferment at 76°F until the dough grows about 40 percent and shows bubbles, roughly 4 to 5 hours total from mixing. Shape, place in a floured banneton, and cold proof overnight, 12 to 16 hours. Bake straight from the fridge in a Dutch oven at 450°F: 20 minutes covered, 20 uncovered, until deeply browned. Cool 2 hours before slicing.

Reading the dough beats watching the clock

Recipes give times; dough gives signals. Bulk fermentation is done when the dough has risen 30 to 50 percent (not doubled, which is over-fermented for most), the surface is domed and slightly bubbly, and it jiggles like set gelatin when you shake the bowl. Temperature runs the whole show: at 70°F bulk takes 6 to 8 hours, at 78°F it takes 3 to 4. A $10 probe thermometer in the dough removes the guesswork. Mark your container with a rubber band at the starting level so you can see 40 percent rise instead of estimating it.

Starter math: feeding ratios explained

A 1:1:1 feeding (equal parts starter, flour, water) peaks in 4 to 6 hours at room temperature. A 1:5:5 feeding peaks in 10 to 12 hours, which is why bakers feed heavy ratios before bed. The ratio does not change the flavor much; it changes the schedule. Use the starter at peak: domed, bubbly, and passing the float test, when it just starts to smell pleasantly sour rather than sharp. A starter that collapses and smells like nail polish is past peak and will make sluggish dough. If yours lives in the fridge, give it 2 feedings at room temperature before bake day to wake it up fully.

Common sourdough mistakes

Cutting the loaf warm is the most painful: the crumb is still setting and turns gummy. Wait the full 2 hours. Slicing with a dull knife compresses the crumb; a sharp serrated blade saws without pressing. Scoring too shallow gives blowouts, too deep deflates; a quarter-inch confident slash at an angle is the target. Storing in plastic kills the crust within hours; a paper bag or bread box keeps it crisp for 2 days. And the classic: feeding the starter with bleached flour or chlorinated water and wondering why it stalls. Unbleached flour and filtered water remove both variables.

Why Baker's Percentages Beat Cups

Baker's math sets the flour at 100 percent and expresses everything else as a share of it, which makes scaling trivial and hydration honest. A recipe with 500 g flour, 375 g water, 100 g starter, and 10 g salt is 75 percent hydration, 20 percent starter, 2 percent salt, no matter whether you make one loaf or ten. Cups cannot do this because a cup of flour weighs anywhere from 120 to 150 grams depending on how you scoop. The percentage system also reveals the recipe's character at a glance: 65 percent hydration is stiff and beginner-friendly, 75 is open-crumbed and slack, 80-plus is advanced territory. Learn to read the numbers and you can judge any recipe before touching flour.

Worked Example: The Weekend Loaf at 75 Percent Hydration

Target: two loaves, 900 g flour total. Water at 75 percent: 675 g. Starter at 20 percent: 180 g, ripe and doubled. Salt at 2 percent: 18 g. Mix flour and water, rest 1 hour (autolyse), add starter and salt, then bulk ferment 4 to 5 hours at around 75 F with folds every 30 minutes for the first 2 hours. The dough should grow about 50 percent, not double; doubling over-proofs most home doughs. Shape, cold-proof overnight in the fridge 12 to 14 hours, then bake straight from the fridge in a preheated Dutch oven: 20 minutes covered at 475 F, 20 uncovered. The cold dough scores cleanly and the oven spring is dramatic. Total hands-on time: under an hour. Total elapsed: a day. The schedule, not the labor, is what makes sourdough feel hard.

Starter Feeding Ratios, Demystified

A 1:2:2 feeding (one part starter, two parts flour, two parts water by weight) peaks in about 4 to 6 hours at room temperature; 1:5:5 peaks in 8 to 12. Higher ratios give you a longer runway, which is why bakers feed 1:5:5 before bed and bake in the morning. The float test is unreliable; a starter can be ripe and not float if degassed by stirring. Trust the signs instead: doubled volume, domed top just starting to flatten, pleasant tangy smell, bubbles throughout. Feed on schedule for a week before judging a sluggish starter; most "dead" starters are just hungry and acidic, and two peak-to-peak feedings at 1:2:2 revives them.

Sourdough Mistakes

Mistake one is watching the clock instead of the dough. Fermentation speed doubles roughly every 15 F of temperature change, so a recipe's "4-hour bulk" is fiction in a 68-degree kitchen. Watch the volume gain and the jiggle, not the timer. Mistake two is underbaking: pale sourdough is gummy sourdough, because the interior needs a dark, caramelized crust to finish setting. Bake darker than feels safe. Mistake three is cutting the loaf hot. The crumb is still setting for at least an hour; slicing early gives gummy slices and the steam escaping ruins the crust. Wait the hour. It is the hardest step in baking.