Cost of a loaf of sourdough
The flour and salt in one loaf of King Arthur's naturally leavened sourdough cost about $0.59. Selling it is a different sum: with 30 minutes of your time for the pair of loaves, a bag and the oven, a loaf costs $5.46, and a 40% margin puts it at $9.09.
What goes into two loaves
The recipe uses 454 g of ripe starter, 600 g of all-purpose or bread flour, 85 g of whole wheat flour, 397 g of water and 15 g of salt, and makes 2 loaves. Water is left out as free. The starter is counted as its flour: assuming a 100% hydration starter (equal weights of flour and water), it is half flour, so 454 g holds about 227 g of it. All-purpose flour is the September 2026 U.S. average of $0.55 a pound from the BLS. Whole wheat flour and salt are my placeholder prices (starred).
| Ingredient | Used | Package | Cost |
|---|---|---|---|
| Flour in the starter (454 g starter) | 227 | $0.55 / 1 | $0.27 |
| All-purpose flour | 600 | $0.55 / 1 | $0.72 |
| Whole wheat flour | 85 | $4.49 / 5 * | $0.17 |
| Table salt | 15 | $1.29 / 26 * | $0.03 |
| Ingredients for the batch | $1.19 | ||
Where the cost of a loaf comes from
| Part | Per loaf |
|---|---|
| Flour and salt | $0.60 |
| Bread bag (my example, $0.40) | $0.40 |
| Your time (15 minutes per loaf at an example $15/hour) | $3.75 |
| Overhead (15%: a long, hot bake) | $0.71 |
| Cost per loaf | $5.46 |
| Price at a 40% margin | $9.09 |
Flour is about a tenth of the cost per loaf, and your time is about two thirds of it. That is why sourdough prices at markets can look high next to a supermarket loaf. For example, if four loaves took the same 30 minutes as two, your time would drop from $3.75 to $1.88 a loaf, a saving of $1.88. A flour that cost 20% less would save only $0.12 a loaf. King Arthur lists 20 minutes hands-on; I used 30 to cover shaping, scoring and cleanup.
The starter between bakes
Keeping a starter alive costs flour too. If you feed 50 g of flour a day and discard the rest, that is 1.5 kg a month, about $1.80 at the average flour price. Baking twice a week makes that roughly $0.23 a bake, small next to your time but worth adding as a line in the calculator if you sell often.
Price your own loaf
Open these two loaves in the calculator and change the flour price, the batch size or your hourly rate. Bread flour, rye or a seeded mix each go in as their own row with the package price and size from your receipt.
If you sell, check how your state treats bread under its cottage food rules before you start. The final price is yours to set; the markup vs margin page helps when you compare it with what other bakers charge.