Carbs in Sourdough Bread: The Quick Answer
Sourdough Bread contains 47.3g of net carbs per 100g, calculated by subtracting 1.8g of dietary fiber from 49.1g of total carbohydrates. With 246.0 calories, 10.5g protein, and 0.9g fat per 100g, it is classified as High Carbs for carbohydrate content.
Net carbs — not total carbs — are what matter for keto and low-carb diets. Only net carbs raise blood sugar and affect insulin, which is why tracking them accurately is key to staying in ketosis. Use our Keto Macro Calculator to find your daily net carb limit based on your body and goals.
Is Sourdough Bread Keto Friendly?
Sourdough Bread is high in carbs with 47.3g net carbs per 100g. It is generally not suitable for strict keto (under 20g net carbs/day) but may fit into a broader low-carb diet depending on portion size and your daily limit.
Best Low-Carb Swaps for Sourdough Bread
Sourdough Bread is high in carbs. If you're eating low-carb or keto, these swaps deliver the same satisfaction with a fraction of the net carbs.
| Instead of | Try this | Why it helps |
|---|---|---|
| Sourdough loaf (~47g net carbs per 100g) | Almond flour bread | ~10g net carbs per 100g — bakes beautifully |
| Sourdough sandwich | Lettuce-wrapped sandwich | Save 20+ grams of carbs per meal |
| Sourdough toast | Portobello mushroom cap, broiled | Hearty, umami-rich base for toppings — under 3g net carbs |
How Net Carbs Are Calculated
Net carbs are calculated by subtracting dietary fiber (and sugar alcohols, if present) from total carbohydrates: Net Carbs = Total Carbs − Fiber. For Sourdough Bread: 49.1g − 1.8g = 47.3g net carbs per 100g.
Dietary fiber is subtracted because it passes through the digestive system without being absorbed as glucose. It does not raise blood sugar or trigger an insulin response, making it irrelevant for carb counting on keto and low-carb diets.