Sourdough Calculator — Bread Recipe by Weight
Enter your target dough weight and the standard baker's percentages for hydration, starter and salt — the calculator instantly scales every ingredient to the gram.
g
%
%
%
Exact ingredient weights by baker's percentage
- 1
Baker's divisor
1 + 0.75 + 0.2 + 0.02 = 1.97Sum of all baker's percentages as decimals plus 1 for the flour — used to back-calculate the flour weight. - 2
Flour weight
800 ÷ 1.97 = 406.1 - 3
Water weight
406.1 × 0.75 = 304.6 - 4
Total dough weight
406.1 + 304.6 + 81.2 + 8.1 = 800
How does this calculator work?
Sourdough ingredients scale from your target weight using baker's percentages: Flour = dough ÷ (1 + hydration + starter + salt). At 800 g dough, 75% hydration, 20% starter, 2% salt: roughly 415 g flour, 311 g water, 83 g starter, 8 g salt — adjust hydration and starter % to suit your style.
Formula
How this is calculated
Baker's percentages express every ingredient as a fraction of the total flour weight, making recipes trivial to scale. The flour is always 100%; every other ingredient is a percentage of it. Hydration (65–80% is typical) controls the dough's stickiness and crumb openness — higher hydration gives a more open, irregular crumb but is harder to shape. Starter or levain (typically 15–25%) provides the wild yeast and bacteria for fermentation; a higher percentage speeds proofing at the cost of long, complex flavour development. Salt (1.8–2.2%) strengthens gluten structure and regulates fermentation speed.
This calculator inverts the formula: given your target total dough weight and the three percentages, it solves for the flour weight first — Flour = dough ÷ (1 + hydration + starter + salt) — and then multiplies by each percentage to produce the individual ingredient weights. This direct approach is the standard used by home bakers and professional formulators.
Note that this model treats starter as a single ingredient rather than decomposing it into its own flour and water. If your levain has a hydration other than 100% (e.g. a stiff starter at 65%), the effective total hydration of the dough will differ slightly from the entered percentage — experienced bakers account for this by adjusting the main water slightly after weighing the levain.
Frequently asked questions
Baker's percentage expresses each ingredient's weight relative to the total flour weight, which is always 100%. 75% hydration means 75 g of water per 100 g of flour. This makes scaling recipes up or down trivial — just multiply or divide every percentage by the same flour weight.
Most beginners start at 65–70%. A 75% dough is soft and open-crumbed but sticky and harder to shape. Wetter doughs (80%+) are used by experienced bakers for highly hydrated batards and ciabatta-style loaves. Whole-grain and rye flours absorb more water, so you may need to increase hydration by 5–10% when substituting them.
Simply change the target dough weight. All ingredient weights scale proportionally. For a typical 900 g tin loaf enter 900 g; for a batard, 700–800 g is common. Note that bread loses around 10–12% of dough weight as steam during baking, so a 800 g dough yields roughly a 700–720 g finished loaf.
Also known as
TG we-Calculate Editorial Team. (2026). Sourdough Calculator — Bread Recipe by Weight [Online calculator]. TG we-Calculate. https://we-calculate.com/calculator/sourdough-calculator
TG we-Calculate Editorial Team. "Sourdough Calculator — Bread Recipe by Weight." TG we-Calculate. 2026. https://we-calculate.com/calculator/sourdough-calculator.
TG we-Calculate Editorial Team, "Sourdough Calculator — Bread Recipe by Weight," TG we-Calculate, 2026. [Online]. Available: https://we-calculate.com/calculator/sourdough-calculator
@misc{wecalculate_sourdough_calculator, title = {Sourdough Calculator — Bread Recipe by Weight}, author = {{TG we-Calculate Editorial Team}}, howpublished = {\url{https://we-calculate.com/calculator/sourdough-calculator}}, year = {2026}, note = {TG we-Calculate} }
Did this calculator help you?