Science
Sourdough Bread Calories and Nutrition: A Clear Breakdown
A slice of sourdough has roughly 120-180 calories. Here's the full nutrition picture and how it compares to other breads.
A typical slice of sourdough bread (about 50g) has roughly 120–180 calories, depending on size and flour, with around 25–35g of carbohydrates, 4–6g of protein, and minimal fat. Its standout feature isn't the calorie count — it's the lower glycemic impact and better mineral availability from fermentation.
Nutrition per slice (≈50g, white sourdough)
| Nutrient | Amount |
|---|---|
| Calories | 120–180 |
| Carbohydrates | 25–35g |
| Protein | 4–6g |
| Fat | 0.5–1.5g |
| Fiber | 1–2g (more if whole grain) |
| Sodium | 200–400mg |
Whole-grain sourdough has more fiber, protein, and micronutrients per slice.
How it compares
| Bread | Calories/slice | Notable |
|---|---|---|
| White sourdough | 120–180 | Lower GI than white bread |
| Whole wheat sourdough | 120–160 | More fiber + minerals |
| Commercial white | 70–100 (thin slices) | Higher GI, additives |
| Multigrain | 100–140 | Varies widely |
Calorie counts are similar to other breads — the real differences are glycemic impact and nutrient absorption, not calories.
The fermentation advantages
- Lower glycemic response. Sourdough acids slow starch digestion, producing a gentler blood-sugar rise than other breads at the same carb level.
- Better mineral absorption. Fermentation breaks down phytic acid, freeing iron, zinc, and magnesium.
- Satiety. The chewy texture and slower digestion can keep you full longer.
Making it more nutritious
- Use whole grains for more fiber and micronutrients.
- Add seeds (flax, sunflower, sesame) for healthy fats and minerals.
- Longer fermentation maximizes the digestibility benefits.
Frequently asked questions
Is sourdough good for a diet?
It's not low-calorie, but its lower glycemic impact and satiety make it a smart bread choice in moderation.
How many carbs are in sourdough?
Roughly 25–35g per slice — similar to other breads, but with a slower, lower blood-sugar response.
Does sourdough have more protein?
Slightly more than typical white bread, especially whole-grain versions, but bread isn't a major protein source.
The most nutritious sourdough is well-fermented and whole-grain. SourdoughAI helps you run the longer ferments that unlock those benefits.