White Net Carbs Calculator helps you quickly find the digestible carbohydrate content in common white foods — cooked white rice, white bread, white pasta, baked white potatoes, white flour, and granulated white sugar. Net carbs are the carbohydrates your body actually absorbs and that affect blood sugar, calculated by subtracting fiber and sugar alcohols from total carbs.
This tool is useful for anyone following a low-carb, keto, or diabetic meal plan, as well as fitness enthusiasts tracking macronutrients. Simply choose a food, enter your serving size in grams or ounces, and hit Calculate. The result shows net carbs for that serving, plus a breakdown of total carbs, fiber, and sugar alcohols so you always know where the numbers come from.
You can also override the fiber or sugar alcohol values if you are using a nutrition label with different data. The calculator works with precise per-100g reference values from USDA FoodData Central.
🍚 White Net Carbs Calculator
Calculate digestible carbs in white rice, bread, pasta, potato, flour, and sugar.
⚙️ Optional adjustments per 100 g
Leave blank to use the food's standard fiber and sugar alcohol values.
📋 How to Use This Calculator
This calculator is built around a simple workflow. Start by selecting the white food you want to analyze from the dropdown. If you cannot find an exact match, choose the closest item and use the optional fiber and sugar alcohol fields to adjust the values to match the label on your product.
- Select a food item, such as cooked white rice, white bread, white pasta, baked white potato, all-purpose flour, or white sugar.
- Enter the serving size in grams or ounces. The preset buttons (50 g, 100 g, 150 g, 200 g) give you quick starting points, and a kitchen scale is the most reliable way to measure.
- Optionally change the fiber or sugar alcohol values per 100 g. Leave these blank if you want to use the standard values listed in the reference table below.
- Click Calculate Net Carbs. The result panel shows your serving's net carbs, total carbs, fiber, sugar alcohols, and a step-by-step breakdown.
- Use the Copy Result button to paste the summary into a food log, spreadsheet, or note.
Net Carbs Formula Explained
Net carbs are not an officially defined term, but the most widely used formula in low-carb and keto communities is:
Fiber is subtracted because most plant fiber passes through the digestive tract without being broken down into glucose. Sugar alcohols such as erythritol, xylitol, and sorbitol are subtracted because they are only partially absorbed and have a smaller impact on blood sugar than regular sugar. Different brands and diet plans handle sugar alcohols differently; for example, some subtract only half of the grams from maltitol. This tool subtracts the full amount by default, so if you follow a more conservative approach (for example subtracting only half of sugar alcohols), you can adjust the sugar alcohol field manually or simply reduce the final result.
The math is straightforward: multiply the per-100 g values by your serving size in grams and divide by 100. For example, if a food has 28.2 g total carbs and 0.4 g fiber per 100 g, a 150 g serving has (28.2 × 150) ÷ 100 = 42.3 g total carbs and (0.4 × 150) ÷ 100 = 0.6 g fiber.
For a higher-fiber comparison, try the artichoke net carbs calculator to see how much fiber can lower the net carb count of a vegetable.
Reference Values for White Foods
The values below are approximate averages based on USDA FoodData Central entries for common white foods. Use them as a starting point, and check the nutrition label when you have one.
| Food (per 100 g) | Total Carbs | Fiber | Net Carbs |
|---|---|---|---|
| White rice, cooked | 28.2 g | 0.4 g | 27.8 g |
| White bread | 49.0 g | 2.7 g | 46.3 g |
| White pasta, cooked | 31.0 g | 1.8 g | 29.2 g |
| White potato, baked flesh | 21.1 g | 2.2 g | 18.9 g |
| White flour, all-purpose | 76.3 g | 2.7 g | 73.6 g |
| White sugar, granulated | 99.8 g | 0.0 g | 99.8 g |
You can look up complete nutrient profiles on the official USDA FoodData Central database.
Worked Examples
Example 1: 150 g cooked white rice
Total carbs: 28.2 g/100 g × 1.5 = 42.3 g
Fiber: 0.4 g/100 g × 1.5 = 0.6 g
Net carbs: 42.3 − 0.6 = 41.7 g
Example 2: 50 g white bread (about 2 thin slices)
Total carbs: 49.0 g/100 g × 0.5 = 24.5 g
Fiber: 2.7 g/100 g × 0.5 = 1.35 g
Net carbs: 24.5 − 1.35 = 23.15 g ≈ 23.2 g
These examples show why serving size matters. A modest 50 g portion of bread already contains roughly 23 g of net carbs, which can consume a large share of a typical 20–50 g daily keto allowance.
Tips for Low-Carb Meal Planning
- Weigh more, measure less. Cups and spoons vary; a digital kitchen scale is the most accurate way to track net carbs.
- Do not forget hidden fiber. Foods like bread and pasta can be fortified with fiber or sugar alcohols. Read the Nutrition Facts label and adjust the optional fields if necessary.
- Replace refined white grains. Swapping white rice for cauliflower rice, zucchini noodles, or shirataki noodles cuts net carbs dramatically.
- Pair white foods with protein and fat. If you eat white rice or potato, combining it with chicken, eggs, avocado, or olive oil can slow digestion and blunt blood sugar spikes.
- Beware of net carb claims on packaged foods. Manufacturers may subtract fiber and sugar alcohols differently; always verify with the label and your own glucose response.
Frequently Asked Questions
Are net carbs the same as impact carbs? Yes, the terms are often used interchangeably. Both refer to carbohydrates that are absorbed and affect blood sugar.
Can I eat white rice on a low-carb diet? In small portions, maybe. A 100 g serving of cooked white rice has about 27.8 g net carbs, which is high relative to a keto target of 20–50 g per day. Measure carefully and plan the rest of your day accordingly.
Why is the net carb value for sugar the same as total carbs? Granulated white sugar has essentially no fiber or sugar alcohols, so all 99.8 g of carbohydrate per 100 g is digestible.
Does the calculator subtract all sugar alcohols? Yes, by default it subtracts 100% of the sugar alcohol grams. If you prefer a more conservative estimate, use the optional field to enter half the sugar alcohol amount for your food.
Are the reference values accurate for my brand? They are averages from USDA FoodData Central. Branded foods can differ, so use the optional override fields when you have a specific product label. You can also use the potato fiber calculator if you want a deeper look at the fiber contribution in white potatoes.