Net Carbs Calculator
Enter the total carbs, fiber, and sugar alcohols from any nutrition label to get net carbs instantly — the number that actually matters on keto and low-carb.
Net carbs at a glance
| Daily net carbs | What it means for keto |
|---|---|
| Under 20 g | Strict keto — reliable ketosis for most |
| 20–30 g | Standard keto range |
| 30–50 g | Low-carb, but often out of ketosis |
| Over 50 g | Moderate-carb — not keto |
Net carbs in popular foods
Net carbs are what's left after fiber and sugar alcohols. (This calculator is one of our 14 free nutrition tools— the keto macro and protein calculators pair well with it.) Here's how everyday foods stack up per typical serving:
| Food | Serving | Net carbs |
|---|---|---|
| Avocado | ½ fruit | 1.5 g |
| Egg | 1 large | 0.4 g |
| Spinach (raw) | 1 cup | 0.4 g |
| Cheddar cheese | 1 oz | 0.4 g |
| Almonds | 1 oz | 2.5 g |
| Broccoli | 1 cup | 3.6 g |
| Strawberries | ½ cup | 3 g |
| Banana | 1 medium | 24 g |
| White rice | 1 cup cooked | 44 g |
Why net carbs and not total carbs?
Fiber and sugar alcohols are carbohydrates on paper, but they aren't digested into blood glucose the way starch and sugar are — so they don't raise blood sugar or knock you out of ketosis. That's why keto and low-carb diets track net carbs: it's the number that reflects the metabolic impact of a food. A few strict approaches count total carbs to be conservative, especially with maltitol-heavy products.
How to keep net carbs low
- Build meals around protein and non-starchy vegetables — leafy greens, broccoli, zucchini.
- Use high-fiber foods (avocado, chia, flax) that stay low in net carbs.
- Watch “keto” treats sweetened with maltitol — count those sugar alcohols conservatively.
- Check labels: total carbs − fiber − sugar alcohols is your real number.
Sources
- USDA FoodData Central — carbohydrate and fiber values per food.
- FDA — carbohydrates on the Nutrition Facts label — how total carbs, fiber, and sugar alcohols are declared.
- Livesey — glycemic impact of polyols — why erythritol subtracts fully and maltitol shouldn't.
Methodology & sources
Net carbs uses the US label method: total carbohydrate minus dietary fiber and sugar alcohols. Fiber and erythritol are largely non-glycemic; other polyols vary, so treat maltitol-heavy products conservatively.
Source: USDA FoodData Central for carb/fiber values and standard nutrition-label definitions.
Frequently asked questions
- How do you calculate net carbs?
- Net carbs = total carbohydrates − fiber − sugar alcohols. Fiber and most sugar alcohols aren't digested into blood glucose the way other carbs are, so keto and low-carb diets count only what's left. A food with 22 g total carbs, 6 g fiber, and 4 g sugar alcohols has 12 g net carbs.
- What are net carbs vs total carbs?
- Total carbs is every gram of carbohydrate on the label. Net carbs subtracts the parts that don't meaningfully raise blood sugar — fiber and sugar alcohols. Keto diets track net carbs; some stricter approaches track total carbs to be safe.
- Do you subtract all sugar alcohols?
- Not equally. Erythritol has almost no blood-sugar impact, so it's fully subtracted. Others like maltitol raise glucose more, so many people subtract only half. This tool subtracts the full amount to match standard label math — if a product uses maltitol, count it more conservatively.
- How many net carbs a day for keto?
- Most people stay in ketosis at 20–30 g of net carbs per day; some need under 20 g. Use this calculator per food and add them up, or let CarbMeNot total your net carbs automatically from a photo.
- Does fiber count as a carb on keto?
- Fiber is technically a carbohydrate, but because it isn't digested into glucose, keto and low-carb diets subtract it to get net carbs. That's why high-fiber, low-net-carb foods like avocado and leafy greens are keto staples.
Related tools
Net carbs from a photo — no label math
CarbMeNot reads the net carbs in any meal automatically. Free on iOS and Android.
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