Lemons may be small, but they bring a bright, tart punch to water, dressings, marinades, and desserts — and they are remarkably low in calories. The Lemon Calories Per Cup Calculator makes it easy to see exactly what a cup, tablespoon, or gram of lemon adds to your daily calorie and nutrient totals. Choose between raw lemon juice and peeled lemon flesh, enter your serving size, and the tool returns calories, carbohydrates, sugar, fiber, protein, and vitamin C.
This calculator is built for anyone tracking calories, counting carbs, following a keto or low-sugar plan, or simply curious about citrus nutrition. Because portion sizes differ so much between juice and fruit segments, the tool uses separate USDA-based density and nutrition values for each form, giving you more reliable numbers than a generic one-lemon entry.
🍋 Lemon Calories Per Cup Calculator
How to Use This Calculator
Start by entering your serving size in the calculator above. You can type the amount in cups, tablespoons, or grams, and the unit selector will automatically convert it to the correct weight for either raw lemon juice or peeled lemon flesh. Then choose the lemon form you are actually using — this matters because 1 cup of juice weighs about 244 g, while 1 cup of peeled flesh weighs about 212 g and has a different nutrition profile.
If you quickly want to see common portions, tap one of the preset buttons (¼ cup, ½ cup, 1 cup, 2 cups). The tool will fill in the amount and run the calculation immediately. Press Calculate Calories any time you change a value manually, and use Reset to return to the default 1-cup juice serving.
Tip: for recipes that call for 'the juice of one lemon,' expect about 2 to 3 tablespoons (roughly 30 to 45 ml). Use the tablespoons unit for that amount.
Nutrition Data Behind the Numbers
The values shown are based on USDA FoodData Central entries for raw lemon juice and raw lemons without peel. For every 100 grams:
| Nutrient | Raw lemon juice | Peeled lemon flesh |
|---|---|---|
| Calories | 22 kcal | 29 kcal |
| Carbohydrates | 6.9 g | 9.32 g |
| Sugars | 2.52 g | 2.5 g |
| Fiber | 0.3 g | 2.8 g |
| Protein | 0.35 g | 1.1 g |
| Fat | 0.24 g | 0.3 g |
| Vitamin C | 38.7 mg | 53 mg |
Source: USDA FoodData Central.
Juice contains more water and fewer calories per cup than flesh, but flesh provides more fiber and vitamin C. If you are eating the whole fruit including membranes (not the peel), the flesh values are the right choice.
Worked Examples
Example 1: 1 cup of raw lemon juice. 1 cup = 244 g. At 22 kcal per 100 g, the total comes to about 54 kcal, 16.8 g carbs, 6.1 g sugar, and 94 mg vitamin C.
Example 2: 2 tablespoons of juice. 2 tbsp = about 31 g. That serving provides only about 7 kcal, 2.1 g carbs, 0.8 g sugar, and 12 mg vitamin C — a reasonable addition to a glass of water or salad dressing.
Example 3: 1 cup of peeled lemon flesh. 1 cup = 212 g. Using the flesh profile, you get about 61 kcal, 19.8 g carbs, 5.9 g fiber, 2.3 g protein, and 112 mg vitamin C.
Tips for Accurate Tracking
- Use a liquid measuring cup for juice and a dry measuring cup for chopped or sectioned flesh. Do not pack the flesh down.
- If a recipe adds sugar, honey, or syrup, those calories are not included in this calculator. Add them separately using your food diary.
- Bottled lemon juice may contain added citric acid or preservatives, and calorie values can differ slightly. Check the product label or use fresh juice for the most accurate result.
- Lemon zest is very low in calories and not included in these estimates; you can ignore it for calorie tracking.
- For meal prep, weigh the lemon portion in grams on a kitchen scale whenever possible — this is more accurate than cup measures.
Keto note: lemon juice has about 6.6 g net carbs per 100 g (6.9 g total carbs minus 0.3 g fiber), while lemon flesh has about 6.5 g net carbs per 100 g. Small servings fit easily into low-carb diets.
Frequently Asked Questions
How many calories are in a whole lemon? A medium lemon (about 58 g of edible flesh without peel) has roughly 17 kcal. The juice from one medium lemon is around 10–12 kcal, depending on how much juice it yields.
Does lemon water have calories? A thin slice of lemon in water adds less than 1 kcal. Squeezing the juice of half a lemon (about 1 tablespoon) adds roughly 3–4 kcal, which is usually negligible but still worth logging if you drink several glasses a day.
Which is healthier: juice or flesh? Both are low-calorie and rich in vitamin C. Flesh has more fiber and a bit more vitamin C per 100 g, while juice is more convenient and slightly lower in calories. Choose based on how you plan to use them.
Can I use this for lemon extract or zest? No. Lemon extract is concentrated and has a different calorie profile, and zest is used in tiny amounts. This calculator is specifically for fresh juice and peeled flesh.
Nutrition values can vary by variety, ripeness, and growing conditions. For other citrus comparisons, see the tangerine calories per cup tool or track lighter produce like lettuce by the cup.