Calories in Lemon

Updated July 2026 · Reviewed by CaloriesCalc Team · Source: USDA FoodData Central

29
kcal
per 100g
9.32
g
Carbs
1.1
g
Protein
0.3
g
Fat
2.8
g
Fiber
31
kcal per medium lemon (108g)
4
kcal per tbsp juice (15ml)
8
kcal per oz (28g)
✔ Very low calorie✔ Excellent vitamin C✔ Rich in citric acid✔ Fat free✔ Gluten free✔ Vegan
Lemon nutrition facts
🛡Excellent vitamin C — 53mg per 100g
🍋Rich in citric acid — prevents kidney stones
Hesperidin for cardiovascular health
🔥Only 29 kcal per 100g
💧Enhances iron absorption from plant foods
🧴Supports collagen synthesis and skin health

🍋 Calculate Calories for Any Lemon Weight

Weight100g

Nutrition Facts

Per 100g (raw lemon)

* % Daily Value based on a 2,000 kcal diet.


Quick summary: Lemons contain just 29 calories per 100g — one of the lowest-calorie fruits. They provide 59% of daily vitamin C per 100g, with citric acid clinically proven to prevent kidney stones. Lemon juice increases plant-based iron absorption by 2–6× when consumed with plant foods. With only 6.5g of net carbs and 2.5g of natural sugar per 100g, lemon is suitable for keto and low-sugar diets.

Vitamins & Minerals — per 100g

NutrientAmount% Daily ValueBar
Vitamin C53.0 mg59%
Potassium138 mg3%
Vitamin B60.08 mg5%
Folate (B9)11 µg3%
Thiamine (B1)0.04 mg3%
Calcium26 mg2%
Magnesium8 mg2%
Phosphorus16 mg2%
Iron0.6 mg3%
Vitamin E0.15 mg1%

Calories in Lemon by Weight

WeightCaloriesCarbsProteinFat

Calories in Different Lemon Servings

ServingWeightCaloriesCarbsNet CarbsFat
1 tbsp lemon juice15ml4 kcal1.3g1.2g0.0g
1 wedge (1/8 lemon)10g3 kcal0.9g0.7g0.0g
⭐ 1 medium lemon (flesh)108g31 kcal10.1g7.1g0.3g
1 large lemon (flesh)139g40 kcal13.0g9.1g0.4g
1 oz28g8 kcal2.6g1.9g0.1g
How does lemon fit your daily calorie goal?
Calculate your TDEE to see exactly how it fits your daily budget
Calculate TDEE →

Macronutrient Breakdown — per 100g

Carbohydrates9.32g · 83% of calories
Protein1.1g · 15% of calories
Fat0.3g · 9% of calories
Fiber2.8g (included in carbs)

Lemon is 89% water with only 2.5g of natural sugar per 100g. The tartness comes from high citric acid content (~5-8g/100g) rather than sugar. Net carbs are 6.5g per 100g — making lemon one of the lowest-sugar citrus fruits.

Micronutrient Highlights

🛡
Vitamin C
53.0 mg
59% Daily Value
Immune support, collagen synthesis, iron absorption
🍋
Citric Acid
~5-8g/100g
Organic acid
Kidney stone prevention, mineral absorption
Potassium
138 mg
3% Daily Value
Blood pressure and heart function
🌿
Fiber
2.8 g
10% Daily Value
Digestive health
🔬
Hesperidin
~50 mg
Flavonoid
Anti-inflammatory, cardiovascular protective
🦴
Vitamin B6
0.08 mg
5% Daily Value
Brain health and energy metabolism

Lemon Health Benefits & Nutrition

Vitamin C and Iron Absorption

Lemons provide 53mg of vitamin C per 100g — 59% of the daily value. Beyond immune support and collagen synthesis, vitamin C from lemon has a specific practical benefit: it dramatically increases absorption of non-haem iron (iron from plant foods). Studies show that consuming lemon juice with plant-based iron sources (beans, lentils, spinach) can increase iron absorption by 2–6 times. This makes lemon juice an important dietary tool for vegetarians and vegans who rely on plant iron.

Citric Acid and Kidney Stone Prevention

Lemon juice is one of the most concentrated dietary sources of citric acid. Citric acid binds to calcium in urine, inhibiting crystal formation and preventing the most common type of kidney stone (calcium oxalate). Research consistently shows that people who drink lemon juice regularly have lower rates of kidney stone formation. A 2007 study found that lemon juice was as effective as prescription potassium citrate for increasing urinary citrate levels in kidney stone patients.

Hesperidin and Cardiovascular Health

Like all citrus fruits, lemons contain hesperidin — a flavonoid concentrated in the peel and white pith. Hesperidin improves blood vessel flexibility (endothelial function), reduces LDL oxidation, and has anti-inflammatory effects. While most of the hesperidin is in the peel rather than the juice, grated lemon zest added to food can significantly increase intake. Lemon zest contains up to 150mg of hesperidin per tablespoon.

Alkalising Effect Despite Acidity

Despite being acidic (pH ~2-3), lemon juice has an alkalising effect on urine once metabolised. The citrate and mineral content is metabolised to bicarbonate, which raises urine pH. The urinary alkalisation from lemon is real and beneficial for kidney stone prevention, even if broader claims about body pH are unfounded.

Is Lemon Suitable for Your Diet?

Weight loss
Excellent — only 29 kcal/100g
Keto
Yes — 6.5g net carbs
Vegan
Yes
Paleo
Yes
Gluten-free
Yes
Diabetic
Yes — very low sugar 2.5g
Low-FODMAP
Juice and small amounts fine
Mediterranean
Core ingredient

Frequently Asked Questions

How many calories in a lemon?
Lemons contain 29 calories per 100g. A medium lemon's edible flesh (108g) has about 31 calories. A tablespoon of lemon juice (15ml) has only 4 calories. Use the slider above to calculate for any weight.
Is lemon water good for you?
Yes, for several reasons. It provides vitamin C and flavonoids, helps increase fluid intake, may improve digestion, and the citrate content helps prevent kidney stone formation. Lemon's acidity can erode tooth enamel with excessive use — rinse with plain water after drinking lemon water.
Does lemon juice help with weight loss?
Modestly. Lemon juice itself (4 kcal per tablespoon) contributes negligibly to calorie intake. The primary weight-loss benefit is indirect: replacing high-calorie beverages with lemon water reduces overall calorie intake significantly.
Is lemon keto?
Yes — lemon is keto-friendly. With only 6.5g of net carbs per 100g and 2.5g of natural sugar, small amounts can be used freely in ketogenic cooking. A tablespoon of lemon juice adds only ~1.2g of net carbs.
How much vitamin C is in a lemon?
A medium lemon (108g of flesh) provides about 57mg of vitamin C — 63% of the adult daily requirement. Per 100g, lemon contains 53mg — comparable to orange (53mg) and slightly less than strawberry (58.8mg) or kiwi (92.7mg).
Can you eat lemon peel?
Yes — lemon zest (the outer yellow layer) is nutritious and flavourful. It is rich in hesperidin, limonene (a terpene with anti-cancer properties in research), vitamin C, and aromatic compounds. Grated lemon zest adds flavour with negligible calories (~1 kcal per teaspoon) and significant polyphenols.

Nutrition values sourced from USDA FoodData Central. Not medical advice.