Lemons are a popular citrus fruit known for their tart flavor and versatility in cooking, baking, and beverages. For those tracking their carbohydrate intake — whether for keto, low-carb, diabetic meal planning, or general nutrition — knowing the exact carb content of lemons is essential. This calculator provides the total carbohydrates, net carbs, and fiber content per 100 grams of lemon, based on USDA nutrition data.
Whether you're squeezing lemon juice over a salad, zesting into a dessert, or adding slices to water, this tool helps you accurately account for the carbs in your diet. Simply enter the weight of your lemon (or use the default 100g reference) and get instant results for total carbs, net carbs (carbs minus fiber), and fiber. Perfect for meal prep, recipe scaling, and daily carb tracking.
🍋 Lemon Carbs Per 100g
How to Use This Tool
Using the Lemon Carbs Per 100g Calculator is straightforward. Enter the weight of your lemon (or lemon portion) in grams. The default is set to 100g, which is the standard reference amount used in nutrition databases. You can also click one of the preset buttons for common lemon sizes: small (58g), medium (84g), large (112g), or the standard 100g reference. After entering or selecting a weight, click the blue Calculate button. The tool will instantly display the total carbohydrates, net carbs (total carbs minus fiber), and fiber content for that specific weight. Use the Reset button to clear results and return to the default 100g input.
Formula Explained
The calculation is based on the USDA National Nutrient Database values for raw lemons (without peel). Per 100 grams of lemon flesh, the composition is:
- Total Carbohydrates: 9.32 g
- Dietary Fiber: 2.8 g
- Net Carbs: 9.32 - 2.8 = 6.52 g
To compute values for any weight, the tool multiplies these per-100g figures by the ratio of your entered weight to 100. For example, for a 58g small lemon: total carbs = 9.32 × (58/100) = 5.41 g; fiber = 2.8 × (58/100) = 1.62 g; net carbs = 6.52 × (58/100) = 3.78 g.
Worked Examples
Total carbs: 9.32 × 0.84 = 7.83 g
Fiber: 2.8 × 0.84 = 2.35 g
Net carbs: 6.52 × 0.84 = 5.48 g
Total carbs: 9.32 × 1.12 = 10.44 g
Fiber: 2.8 × 1.12 = 3.14 g
Net carbs: 6.52 × 1.12 = 7.30 g
Total carbs: 9.32 × 0.15 = 1.40 g
Fiber: 2.8 × 0.15 = 0.42 g
Net carbs: 6.52 × 0.15 = 0.98 g
Reference Table: Lemon Carbs by Weight
| Weight (g) | Total Carbs (g) | Fiber (g) | Net Carbs (g) |
|---|---|---|---|
| 50 | 4.66 | 1.40 | 3.26 |
| 58 (small) | 5.41 | 1.62 | 3.78 |
| 84 (medium) | 7.83 | 2.35 | 5.48 |
| 100 | 9.32 | 2.80 | 6.52 |
| 112 (large) | 10.44 | 3.14 | 7.30 |
| 150 | 13.98 | 4.20 | 9.78 |
| 200 | 18.64 | 5.60 | 13.04 |
Common Mistakes to Avoid
- Including the peel: The carb values in this calculator are for the flesh (pulp) of the lemon without the peel. Lemon peel contains additional fiber and a slightly different carb profile. If you eat the peel, the numbers will differ.
- Confusing lemon juice with whole lemon: Lemon juice has a similar carb density but slightly different fiber content (juice has almost no fiber). For juice-only calculations, use the weight of the juice, not the whole fruit.
- Forgetting to account for added sugar: If you're using lemon in a recipe that adds sugar (e.g., lemonade, lemon bars), the carb count will increase significantly. This calculator only covers the lemon itself.
Frequently Asked Questions
Are lemons keto-friendly?
Yes, lemons are considered keto-friendly in moderate amounts. With only about 6.5g of net carbs per 100g, a squeeze of lemon juice (around 1g net carbs per tablespoon) can easily fit into a daily keto carb limit of 20-50g. However, drinking large amounts of lemon juice or eating whole lemons frequently could add up.
How does lemon carb content compare to other citrus fruits?
Lemons are lower in carbs than oranges (about 12g net carbs per 100g) and grapefruit (about 9g net carbs per 100g), but slightly higher than limes (about 5g net carbs per 100g). Lemons are a good low-carb citrus option.
Can I use this calculator for lemon zest?
Lemon zest (the outer yellow part of the peel) has a different nutritional profile. It contains more fiber and essential oils but less sugar than the flesh. This calculator is designed for the flesh only. For zest, you would need a separate reference.
Where does the data come from?
The values are sourced from the USDA FoodData Central database, specifically for raw lemons (without peel). This is a reliable, government-maintained nutrition reference.