How Many Calories in Fennel? Nutrition Facts & Macros
A cup of sliced fennel (87 g) has 27 calories
Protein 1.1g · Carbs 6.4g · Fat 0.2g
Fennel is a crunchy, anise-flavored vegetable popular in Mediterranean and European cuisine. With only 31 kcal per 100 g, it is a low-calorie choice that delivers good potassium (414 mg per 100 g) and decent fiber (3.1 g). Traditionally used to soothe digestion, fennel is also a solid source of vitamin C (12 mg) and manganese (0.191 mg) per 100 g. Here is everything you need to know about fennel calories and macros, based on USDA data. Fennel is approximately 90% water by weight.
130 kJ · per 100g · Water: 90.21 g
Calorie Calculator: Fennel (Raw)
87 g Fennel (Raw) contains 27 kcal
Calories by Portion Size
| Portion | Calories | Protein | Carbs | Fat |
|---|---|---|---|---|
| 1 cup sliced (87 g) | 27 kcal | 1.1g | 6.4g | 0.2g |
| 1 medium bulb (234 g) | 73 kcal | 2.9g | 17.1g | 0.5g |
| 100 grams | 31 kcal | 1.2g | 7.3g | 0.2g |
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Fennel (Raw) — Nutrition Facts
| Fennel (Raw) | per 100g |
|---|---|
| Calories | 31 kcal |
| Protein | 1.24 g |
| Fat | 0.2 g |
| Carbs | 7.3 g |
| Fiber | 3.1 g |
| Sugar | 3.93 g |
| Sodium | 52 mg |
| Potassium | 414 mg |
| Magnesium | 17 mg |
| Phosphorus | 50 mg |
| Vitamin C | 12 mg |
| Vitamin B6 | 0.047 mg |
| Folate | 27 mcg |
| Manganese | 0.191 mg |
| Water | 90.21 g |
Source: USDA FoodData Central (FDC ID: 169385) · Data verified April 2026
Variations
Raw (default)
31 kcal per 100 g. Raw fennel is crisp and refreshing with a mild anise flavor. Best sliced thin in salads, used as a crudité, or eaten as a crunchy snack. The high water content (90%) makes it hydrating and the fiber (3.1 g) aids digestion.
Roasted
Approximately 45 kcal per 100 g (estimate, depends on oil used). Roasting caramelizes the natural sugars, making fennel sweeter with a milder anise flavor. The texture becomes tender and golden. A popular side dish in Mediterranean cuisine — toss with olive oil, salt, and pepper at 200 °C for 25-30 minutes. Pairs well with fish, chicken, and pork.
Dietary Perspectives
For Weight Loss
Fennel is excellent for weight loss. At just 31 kcal per 100 g, a full cup of sliced fennel (87 g) has only about 27 calories. The high water content (90%) and good fiber (3.1 g per 100 g) make it filling and satisfying. The natural anise flavor adds a pleasant sweetness without any sugar. Fennel tea is a traditional digestive aid with essentially zero calories — a great alternative to sugary drinks. Roasted fennel makes a satisfying side dish that feels indulgent while staying low-calorie.
For Athletic Performance
Fennel provides good potassium (414 mg per 100 g) — helpful for electrolyte balance during and after exercise. It is also a traditional digestive aid; fennel tea after heavy meals can ease stomach discomfort. However, fennel is not a significant calorie or protein source (31 kcal, 1.24 g protein per 100 g), so it should complement rather than replace energy-dense foods. Use it as a crunchy, hydrating side dish alongside your main meals. The fiber (3.1 g) supports gut health without causing heaviness.
For Keto
Fennel is very keto-friendly with only 4.2 g net carbs per 100 g (7.3 g total carbs minus 3.1 g fiber). A cup of sliced fennel (87 g) has approximately 3.7 g net carbs — easily fitting into a 20 g daily limit. The good fiber content (3.1 g) supports digestion, which is important on keto. Roast fennel with olive oil and parmesan for a satisfying keto side dish. Use raw fennel in salads for crunch. The anise flavor pairs exceptionally well with fish and pork — both keto staples. Fennel tea is a zero-calorie drink option.
Frequently Asked Questions
How many calories are in fennel?
A cup of sliced fennel (87 g) contains about 27 calories. One medium bulb (234 g) has approximately 73 calories. Per 100 g, raw fennel has 31 kcal — making it a very low-calorie vegetable. For comparison, celery has 14 kcal and onion has 40 kcal per 100 g.
Is fennel healthy?
Fennel is very healthy. It provides 414 mg of potassium per 100 g (more than many fruits), 12 mg of vitamin C, and 3.1 g of fiber. It is rich in manganese (0.191 mg) and contains 27 mcg of folate. Traditionally, fennel has been used as a digestive aid — fennel tea is a well-known remedy for bloating and stomach discomfort. The high water content (90%) makes it hydrating.
How many carbs are in fennel?
Raw fennel has 7.3 g of total carbs per 100 g, with 3.1 g of fiber and 3.93 g of sugar. That gives about 4.2 g of net carbs per 100 g. A cup of sliced fennel (87 g) has approximately 6.4 g total carbs and 3.7 g net carbs. Most of the sugar is natural fructose and glucose.
What does fennel taste like?
Raw fennel has a crisp, crunchy texture with a mild anise (licorice) flavor. The taste is sweet and refreshing, much milder than anise seed or star anise. When roasted, the anise flavor mellows significantly and the fennel becomes sweeter and caramelized. The fronds (feathery tops) have a more intense herbal flavor and work well as a garnish.
Is fennel good for weight loss?
Fennel is excellent for weight loss. At 31 kcal per 100 g, a full cup of sliced fennel (87 g) has just 27 calories. The high water content (90%) and good fiber (3.1 g per 100 g) promote satiety. Fennel tea is a traditional digestive aid with essentially zero calories. The natural anise sweetness can help satisfy cravings without added sugar. Roasted fennel makes a satisfying low-calorie side dish.
Is fennel keto-friendly?
Fennel is very keto-friendly. Per 100 g it has 7.3 g total carbs minus 3.1 g fiber = about 4.2 g net carbs. A cup of sliced fennel (87 g) has approximately 3.7 g net carbs, which fits easily into a 20 g daily limit. Roast fennel with olive oil and parmesan for a delicious keto side dish. Raw fennel works great in salads for crunch, and pairs well with fish and pork.
Compare with Similar Foods
| Portion | kcal | Protein | Carbs | Fat |
|---|---|---|---|---|
| Fennel (Raw) | 31 | 1.24g | 7.3g | 0.2g |
| Celery (Raw) | 14 | 0.69g | 2.97g | 0.17g |
| Onion (Raw) | 40 | 1.1g | 9.34g | 0.1g |
| Artichoke (Raw) | 47 | 3.27g | 10.51g | 0.15g |
| Leek (Raw) | 61 | 1.5g | 14.15g | 0.3g |
per 100g
Per 100 g, raw fennel has 31 kcal with 1.24 g of protein, 0.2 g of fat, and 7.3 g of carbs (3.1 g fiber). It is comparable to celery (14 kcal) and lower in calories than onion (40 kcal), while offering more fiber and potassium than both.
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