Starter Discount Calculator

The calculator below applies starter discount automatically. Set levain % and levain hydration — the "flour to add" and "water to add" outputs are what you actually weigh out on your counter.

Flour to add
450 g
Water to add
325 g
Salt
10 g
Levain @ 100%
100 g
Total dough
885 g
Effective hydration
75%
How the math works

Total water = flour × hydration %. Your levain contributes 50 g flour + 50 g water — both count toward the totals. You add only the remainder as fresh flour and water.

Salt % is computed on total flour weight, not final-dough flour.

Open 75% hydration guide →

To bake this recipe you need

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The math, explained

If you're using a 100% hydration levain at 20% of recipe flour weight, the levain contributes 10% of recipe flour weight in flour and 10% in water. A stiff (50% hydration) levain at 15% of recipe flour contributes 10% flour and 5% water. The calculator above handles the math for both — you only see the "flour to add" and "water to add" rows, which are the actual weights you measure.

The gear that makes the math work

A short, honest baking kit. The scale matters most — every weight on this page is in grams. The Dutch oven is what turns a good crumb into a great crust.

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  • Digital kitchen scale (0.1 g)Digital kitchen scale (0.1 g)

    Baker's percentage is by weight, not volume — a 0.1 g scale is what makes the math on this page accurate.

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  • Dutch oven / combo cookerDutch oven / combo cooker

    Traps steam for the first bake phase — the single biggest factor in oven spring and a blistered, glossy crust.

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  • Banneton proofing basketBanneton proofing basket

    Wicks moisture and holds shape during the final proof, so high-hydration dough doesn't spread flat.

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  • Bread lameBread lame

    A sharp lame scores clean ears — the cut that decides whether the loaf opens up or bursts at the side.

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  • Bench scraperBench scraper

    Steel scraper handles wet, sticky high-hydration dough without tearing the gluten you just built.

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  • High-protein bread flourHigh-protein bread flour

    The math assumes ~12–14% protein. Real bread flour absorbs the hydration you calculate — all-purpose won't.

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  • Danish dough whiskDanish dough whisk

    Mixes shaggy, high-hydration dough in seconds without the gluey mess of a spoon or your hands.

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Or learn the craft by ear

The numbers here are the what; a good baking book is the why. An Audible trial gets you any title free — Michael Pollan’s Cooked(the “Air” chapter is the best story ever told about why bread rises) is a perfect first listen.

Start a free Audible trial →

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Gear guides — what actually matters

Common questions

What is the starter discount?

Your levain contains flour and water that count toward the recipe's total flour and water. Subtracting the levain's contribution from the ingredients you weigh out is called the starter discount. Without it, dough is typically 2-4% over-hydrated.

How is starter discount calculated?

levain_weight = recipe_flour × levain_pct. levain_flour = levain_weight / (1 + levain_hydration/100). levain_water = levain_weight - levain_flour. final_flour = recipe_flour - levain_flour. final_water = recipe_water - levain_water.