How Many Calories Are in a Lemon? | The Nutritional Scoop

Lemons have a reputation for being too tart to eat plain, so most people assume the calorie count is basically zero. But if you’ve ever squeezed half a lemon into your water or zested one over a salad, you might wonder whether those few drops add up.

The honest answer is that a whole lemon packs only a tiny caloric punch — roughly the same as a single bite of an apple. This article breaks down the exact calorie range for different lemon sizes, what nutrients those calories come with, and how lemons compare to other citrus fruits for calorie-conscious eaters.

Calories in a Lemon: The Basic Numbers

A medium lemon about 2⅛ inches in diameter and weighing 58 grams supplies roughly 17 calories according to Verywell Fit’s nutrition profile. Other sources list up to 24 calories per whole fruit because lemons vary naturally in size and water content.

Per 100 grams, lemons deliver about 29 calories. That’s extremely low compared to most fruits — for reference, an apple has about 52 calories per 100 grams.

Nearly all these calories come from carbohydrates: roughly 5.4 grams total, including 1.6 grams of fiber. The net carbs (carbs minus fiber) land around 3.9 grams per lemon. Fat and protein are minimal, with 0.2 grams and 0.6 grams respectively.

Why Lemons Are Practically a Free Food

People watching their weight often look for ways to add flavor without adding many calories. Lemons are one of the best options because even a whole fruit contributes almost nothing to your daily total. But the form you use makes a difference.

• Whole lemon vs. juice: A whole medium lemon has 17–24 calories, but you’re unlikely to eat the entire fruit. One tablespoon of lemon juice (about 15 grams) has roughly 4 calories.
• Lemon zest: The zest holds essential oils and intense flavor with fewer than 1 calorie per teaspoon — effectively free for calorie counters.
• Lemon water: Squeezing half a lemon into a glass of water adds about 3–6 calories, making it a nearly zero-calorie beverage.
• Lemonade trap: Bottled or homemade lemonade is a different story. A typical 8-ounce glass can pack 100–150 calories from added sugar.
• Organic vs. conventional: Organic lemons average about 26 calories per 100 grams, slightly less than conventional ones at 29 per 100 grams, but the difference is negligible for most uses.

So when you’re tracking calories, lemons themselves are practically irrelevant. The calories come from what you add — sugar, honey, or pairing with high-calorie foods. For weight management, lemons are a freebie.

Lemon Nutrition Breakdown

The USDA’s SNAP-Ed program defines a standard serving as one whole lemon (58 grams) — see their standard lemon serving size for reference. Lemons are 88–89 percent water and about 10 percent carbohydrates, with both natural sugars (roughly 2.8 grams) and fiber (1.6 grams) contributing to the total.

Micronutrients are where lemons really stand out. One medium lemon provides about 30 mg of vitamin C, which is roughly 40 percent of the Daily Value per fruit. Per 100 grams, the vitamin C content reaches 53 mg — that’s 59 percent of the DV. Lemons also supply small amounts of vitamin B6, potassium, and beneficial polyphenols.

The calorie count per serving stays remarkably consistent. Per the USDA, one whole lemon contributes 17 calories. If you’re using only juice or zest, those numbers drop even further, making lemons an easy addition to almost any eating plan.

Nutrient	Per Medium Lemon (58g)	Per 100g
Calories	17–24	29
Carbohydrates	5.4 g	9.3 g
Fiber	1.6 g	2.8 g
Protein	0.6 g	1.1 g
Fat	0.2 g	0.3 g
Vitamin C	~30 mg	53 mg

As the table shows, the calorie contribution is tiny, but the vitamin C boost is substantial. One lemon gives you a meaningful chunk of your daily vitamin C needs with almost no caloric cost.

How to Use Lemons Without Wrecking Your Calorie Count

The easiest way to keep lemon calories negligible is to use the fresh fruit itself rather than processed products. Here are some practical tips for adding lemon flavor while staying on track:

1. Squeeze over meals: A single wedge of lemon adds only 1–2 calories per squeeze and brightens vegetables, fish, and salads without extra fat or sodium.
2. Infuse your water: Drop a few thin lemon slices into a pitcher of water. The flavor absorbs into the water, and each glass contains just 2–4 calories from the residual juice.
3. Use zest for flavor: Lemon zest contains concentrated essential oils and intense citrus taste with virtually no calories — perfect for dressings, yogurt, or baked goods.
4. Make a lemon vinaigrette: Combine fresh lemon juice with vinegar, herbs, and a tiny amount of oil for a low-calorie salad dressing that cuts the need for heavy cream-based options.
5. Check bottled lemon juice: Some brands add sugar or preservatives. Always read the label, or better yet, use fresh lemons to keep calories minimal.

By using the fruit itself, you get the nutritional benefits — vitamin C and fiber from the pulp — while keeping calories to a minimum. Lemon juice in cooking also reduces the need for salt and heavy sauces.

Comparing Lemon Calories to Other Citrus Fruits

When you look at the citrus family, lemons sit at the low end of the calorie scale. Healthline’s medium lemon calories page provides a handy nutrient breakdown and places lemons alongside oranges, limes, and grapefruit for comparison.

Oranges are significantly higher: a medium navel orange has about 62 calories, more than triple a lemon. Limes are similar to lemons, coming in at around 20 calories each. Grapefruit (half a medium fruit) supplies approximately 52 calories.

So if you’re counting calories, lemon and lime are your best bets. The trade-off is that oranges and grapefruit offer more sugar and calories alongside higher doses of vitamin C per serving. For most purposes, though, lemon provides a solid vitamin C boost at a fraction of the calorie cost.

Fruit	Calories per Medium Fruit	Vitamin C (% DV)
Lemon	20	~40%
Lime	20	~32%
Orange	62	~88%
Grapefruit (half)	52	~64%

The Bottom Line

Lemons are among the lowest-calorie fruits you can eat. A whole lemon adds only about 17–24 calories while delivering a solid dose of vitamin C, fiber, and antioxidants. Whether you use the juice, zest, or slices, you can brighten meals and drinks without worrying about the calorie count.

For precise calorie tracking tailored to your specific diet and health goals, a registered dietitian can help fit lemons and other citrus into your daily plan. Seasonal lemon varieties at your local market may differ slightly in sugar content, so checking with your grocer for current produce is a smart habit.