Calories in Cucumber

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

15
kcal
per 100g
3.63
g
Carbs
0.65
g
Protein
0.11
g
Fat
0.5
g
Fiber
45
kcal per whole cucumber (301g)
8
kcal per cup sliced (119g)
4
kcal per oz (28g)
✔ Extremely low calorie✔ 96% water✔ Virtually zero fat✔ Gluten free✔ Vegan✔ Keto friendly
Cucumber nutrition facts and calories per 100g
💧96% water — most hydrating vegetable
🔥Only 15 kcal per 100g
😌Keto friendly — 2.2g net carbs
🌿Contains cucurbitacins — anti-cancer
🛡Vitamin K — 16µg per 100g
❄️Anti-inflammatory flavonoids

🥒 Calculate Calories for Any Cucumber Weight

Weight100g

Nutrition Facts

Per 100g (raw cucumber)

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


Quick summary: Cucumbers contain just 15 calories per 100g with 96% water content — the most hydrating common vegetable. With only 3.1g of net carbs per 100g, cucumber is fully keto-compatible and suitable for all diets. The skin contains most nutrients including vitamin K (14% DV) and cucurbitacins — compounds with anti-cancer properties in laboratory research.

Vitamins & Minerals — per 100g

NutrientAmount% Daily ValueBar
Vitamin K16.4 µg14%
Potassium147 mg3%
Vitamin C2.8 mg3%
Magnesium13 mg3%
Vitamin A (RAE)5 µg1%
Folate (B9)7 µg2%
Calcium16 mg1%
Phosphorus24 mg2%
Vitamin B60.04 mg2%
Iron0.28 mg2%

Calories in Cucumber by Weight

WeightCaloriesCarbsProteinFat

Calories in Different Cucumber Servings

ServingWeightCaloriesCarbsNet CarbsFat
6 slices60g9 kcal2.2g1.9g0.1g
½ cucumber150g23 kcal5.4g4.6g0.2g
⭐ 1 whole cucumber301g45 kcal10.9g9.3g0.3g
1 cup sliced119g18 kcal4.3g3.7g0.1g
1 oz28g4 kcal1.0g0.9g0.0g
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Macronutrient Breakdown — per 100g

Carbohydrates3.63g · 79% of calories
Protein0.65g · 17% of calories
Fat0.11g · 7% of calories
Fiber0.5g (included in carbs)

Cucumber is 96% water — the highest water content of any common vegetable. Net carbs are 3.1g per 100g. The skin contains most of the fiber and nutrients — eating cucumber with skin is recommended.

Micronutrient Highlights

🛡
Vitamin K
16.4 µg
14% Daily Value
Blood clotting and bone health
💧
Water
96%
Hydration
Most hydrating common vegetable
Potassium
147 mg
3% Daily Value
Blood pressure support
🌿
Cucurbitacins
Trace
Phytochemical
Anti-cancer and anti-inflammatory in research
🔬
Magnesium
13 mg
3% Daily Value
Muscle and nerve function
🧠
Vitamin B6
0.04 mg
2% Daily Value
Brain health

Cucumber Health Benefits & Nutrition

Hydration — 96% Water

Cucumber has the highest water content of any common vegetable at 96%. This makes it exceptionally effective for hydration — eating 300g of cucumber delivers nearly a cup of water along with electrolytes (potassium, magnesium). Research on hydration through food ('eating your water') shows that water-rich foods maintain hydration more effectively than plain water alone because they provide electrolytes alongside fluid. This makes cucumber valuable for hydration, particularly in hot weather or after exercise.

Cucurbitacins and Cancer Research

Cucumbers contain cucurbitacins — bitter triterpenoid compounds that have shown anti-cancer properties in laboratory and animal studies. Cucurbitacin B has been found to inhibit cancer cell growth and induce apoptosis (programmed cell death) in breast, prostate, and liver cancer cell lines. Cucurbitacin E inhibits the JAK-STAT signalling pathway involved in cancer cell proliferation. While human clinical trials are lacking, the preclinical evidence is promising and cucumber consumption is associated with lower inflammation markers in population studies.

Blood Sugar Management

Cucumber has an extremely low glycemic index (~15) and only 2.2g of net carbs per 100g, making it one of the safest foods for blood sugar management. Research suggests cucumber extract may inhibit alpha-glucosidase — an enzyme that breaks down dietary starch into glucose. This enzyme-inhibiting effect slows glucose absorption, similar to some diabetes medications. Regular cucumber consumption is associated with improved glucose tolerance in animal studies.

Skin and Anti-Ageing

Cucumbers have long been used topically and consumed for skin benefits. Silica in cucumber supports collagen synthesis — the structural protein maintaining skin elasticity. Vitamin C and various antioxidants reduce oxidative damage to skin cells. The high water content supports skin hydration from within. Caffeic acid and ascorbic acid in cucumber reduce water retention in skin tissue, explaining the traditional use of cucumber slices on eyes to reduce puffiness.

Is Cucumber Suitable for Your Diet?

Weight loss
Excellent — only 15 kcal/100g
Keto
Yes — 3.1g net carbs
Vegan
Yes
Paleo
Yes
Gluten-free
Yes
Diabetic
Yes — GI ~15
Low-FODMAP
Yes
Mediterranean
Yes

Frequently Asked Questions

How many calories in a cucumber?
Cucumbers contain 15 calories per 100g. A whole cucumber (301g) has 45 calories. A cup of sliced cucumber (119g) has 18 calories. Use the slider above for any weight.
Is cucumber good for weight loss?
Yes — cucumber is ideal for weight loss. At only 15 kcal per 100g with 96% water content, it provides maximum volume and hydration with minimal calories. It can be eaten freely on virtually all calorie-restricted diets. The water and fiber content promote satiety.
Is cucumber keto?
Yes. Cucumber has only 3.1g of net carbs per 100g, making it one of the most keto-friendly vegetables. A whole cucumber provides just 9.3g of net carbs, fitting comfortably within daily keto limits.
Should you eat cucumber with or without skin?
With skin — the skin contains the majority of the fiber, vitamin K, and antioxidants. Peeled cucumber loses about 30% of its nutritional value. Wash thoroughly before eating with skin. If buying conventionally grown cucumbers, the wax coating can be scrubbed off with warm water.
Does cucumber reduce bloating?
Yes. Cucumber has anti-inflammatory properties from quercetin and other flavonoids. Its high water content helps flush excess sodium that causes water retention. Eating cucumber regularly is associated with reduced bloating and water retention, particularly for people with high-sodium diets.
Is cucumber a fruit or vegetable?
Botanically, cucumber is a fruit (it contains seeds and develops from a flower). Culinarily, it is used and classified as a vegetable. Like tomatoes, peppers, and zucchini, it is a botanical fruit treated as a culinary vegetable.

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