Fruit

Lemon nutrition, down to the gram.

The number most people want first: 1 lemon (2-1/8 in dia) holds 17 calories, alongside 0.6 g of protein. The record behind it is USDA’s “Lemons, raw, without peel”. Beyond the headline number, it is notable for vitamin C. The panel underneath takes any serving and any amount, and the vitamin and mineral table tracks what you pick.

By Alen Yaco · Updated 20 September 2026

Every value traces to USDA FoodData Central (167746); Daily Values follow the FDA label rules.

How many calories does lemon have?

1 lemon (2-1/8 in dia) is 17 calories. Per 100 g it is 29. USDA publishes the serving weights below, so these are measured portions rather than rounded guesses.

How much protein does lemon provide?

There are 0.6 g of protein in 1 lemon (2-1/8 in dia), or 1 percent of the 50 g the FDA uses as a daily reference. There is next to no protein in lemon; nearly all of its energy is carbohydrate.

Looked at as a share of calories: carbohydrate 84 percent, fat 6 percent, protein 10 percent.

Choosing and using lemon

Lemons are highly acidic citrus fruits, usually sold fresh as whole yellow fruit or as bottled juice. Look for specimens that feel heavy for their size, which indicates plenty of juice. The skin should have a bright yellow colour and a fine texture. Avoid pale green skins or soft, dull patches.

Heat reduces the bright sharpness of the juice, so add it at the very end of preparation. The white pith beneath the yellow zest is intensely bitter and should never be grated into dishes. A common mistake is squeezing cold fruit, which yields far less juice than fruit warmed to room temperature.

Lemon juice cuts through rich fats, balancing Mediterranean olive oil, grilled fish, and roasted meats. The grated zest provides aroma to British bakes and French sauces without adding liquid. It also prevents sliced orchard fruit from turning brown through enzymatic browning, making it useful in raw salads.

Lemon: the full nutrient profile

Against the Daily Value, 1 lemon (2-1/8 in dia) stands out for vitamin C at 34 percent of a day. The table follows the selector above, so change the serving or the method and it updates.

There are 2.8 g of fibre in 100 g, roughly 10 percent of the daily figure.

Where lemon fits in a day

1 lemon (2-1/8 in dia): 1 percent of 2,000 calories, 1 percent of the protein Daily Value. Those are reference numbers; the TDEE calculator finds yours, and the macro calculator converts them to grams.

Recipes that start with lemon

The Calorie Counter Team wrote these. Under every recipe the numbers are added up from the USDA record for each ingredient and split across the servings.

Snack · British

Traditional Lemon Curd

A sharp, smooth spread made from egg yolks, sugar, and fresh lemon juice cooked gently on the hob.

25 min · serves 4

322kcal

3.1gprotein

21gfat

33gcarbs

Ingredients

• Fresh lemon juice 100 g
• Grated lemon zest 10 g
• Egg yolks 70 g
• Caster sugar 120 g
• Unsalted butter 80 g

Method

1. Whisk the egg yolks and caster sugar together in a heatproof bowl until combined.
2. Stir in the lemon juice, lemon zest, and unsalted butter.
3. Place the bowl over a saucepan of simmering water, ensuring the water does not touch the bowl.
4. Stir the mixture constantly with a wooden spoon for 15 minutes until it thickens enough to coat the back of the spoon.
5. Remove from the heat and pour into a sterilised glass jar to cool.

Nutrition per serving, calculated across 5 USDA ingredient records. Expect small differences once cooked.

Dinner · Mediterranean

Lemon and Herb Roasted Chicken Thighs

Chicken thighs roasted in the oven with sliced whole lemons, garlic, and dried oregano.

45 min · serves 2

722kcal

43gprotein

57gfat

11gcarbs

Ingredients

• Bone-in skin-on chicken thighs 500 g
• Fresh lemons, sliced 150 g
• Olive oil 30 g
• Garlic cloves, sliced 15 g
• Dried oregano 3 g
• Table salt 6 g

Method

1. Preheat the oven to 200 degrees Celsius.
2. Toss the chicken thighs, lemon slices, sliced garlic, olive oil, dried oregano, and salt together in a baking dish.
3. Arrange the chicken thighs skin-side up with the lemon slices placed around them.
4. Roast in the oven for 35 minutes until the chicken skin is brown and the internal temperature reaches 75 degrees Celsius.
5. Rest the chicken for 5 minutes before serving.

Per serving, from 6 USDA FoodData Central records. Cooking changes weight and some nutrients; treat these as close rather than exact.

Side · Greek

Greek Lemon Potatoes

Potato wedges baked in a mixture of lemon juice, vegetable stock, and olive oil until tender and crisp.

60 min · serves 4

216kcal

3.5gprotein

10gfat

29gcarbs

Ingredients

• Russet potatoes, peeled and cut into wedges 600 g
• Fresh lemon juice 80 g
• Olive oil 40 g
• Vegetable stock 150 g
• Garlic cloves, minced 10 g
• Dried oregano 4 g
• Table salt 5 g

Method

1. Preheat the oven to 200 degrees Celsius.
2. Arrange the potato wedges in a single layer in a large baking dish.
3. Whisk the lemon juice, olive oil, vegetable stock, minced garlic, dried oregano, and salt together in a jug.
4. Pour the liquid mixture over the potatoes in the dish.
5. Bake for 50 minutes, turning the potatoes once halfway through, until they are tender and the edges are brown.

Nutrition per serving, calculated across 7 USDA ingredient records. Expect small differences once cooked.

Calorie Counter Team, food critic

One meal, costed: lemon

A sample plate, not a prescription: lemon plus two sides, each line sourced and the sum shown.

Lemon against other fruit

Compared gram for gram, with the form of each food stated. Follow any link for that food’s full page.

Questions about lemon

How many calories does 1 lemon (2-1/8 in dia) have?

17 calories, according to USDA FoodData Central: the record is “Lemons, raw, without peel”, FDC 167746. That works out at 29 per 100 g.

How much protein does lemon have?

1 lemon (2-1/8 in dia) has 0.6 g of protein. By weight that is 1.1 g per 100 g, and the serving covers 1 percent of the Daily Value.

Can you eat lemon when trying to lose weight?

That depends on the rest of the day, not on lemon. For planning: 1 lemon (2-1/8 in dia) is 17 calories and 0.6 g of protein, 15 percent protein by energy, which means it needs a protein-rich partner on the plate.

Is lemon high in carbs?

5.4 g in 1 lemon (2-1/8 in dia), of which 1.6 g is fibre and 1.5 g is sugar.

How do you get the most juice from a lemon?

Warm the fruit to room temperature and roll it firmly against the counter under your palm before cutting. Squeezing with a metal hinge press extracts significantly more liquid than squeezing by hand.

Can you preserve lemons if you cannot use them fresh?

Yes, slice them and freeze the pieces on a tray before transferring them to bags. Alternatively, pack whole or sliced fruit in coarse salt, which preserves the rinds for use in North African stews.

Sources

• Lemons, raw, without peel — USDA FoodData Central, FDC ID 167746
• Daily Values for nutrition labelling, 21 CFR 101.9