18 %
Potassium contributes to normal functioning of the nervous system and to normal muscle function.
How many calories are in fennel?
9.6kcal
in an 80 g portion
12 kcal per 100 g.
Source: UK CoFID 2021, record 13-241. Checked 5 October 2026.
0.16 gFat
0.72 gProtein
1.9 gFibre
18 %Daily potassium
What’s in an 80 g portion
More than half of a portion is water, which is why the calories stay low. What is left is mostly fibre.
- 0.16 gFat
- 0.72 gProtein
- 1.4 gCarbohydrate
- 1.9 gFibre
- 75.4 gWater
- 0.4 gMinerals and the rest
Below average for vegetables
Fennel is 12 kcal per 100 g. The 240 vegetables in this database average 59.9.
Fennel12
Vegetables average59.9
Low in sugar, almost no salt
Low sugars and very low salt by UK labelling rules, per 100 g.
Sugars, per portion1.4 g
Salt, per portion0.02 g
Vitamins and minerals in fennel
Two of the 16 reach the “source of” level, potassium first; none reaches “high in”.
None recorded
- Vitamin D
- Vitamin B12
Show all 16 with amounts
Potassium352 mg, 18 %
Folate0.0336 mg, 17 %
Vitamin C4 mg, 5 %
Thiamin (vitamin B1)0.05 mg, 4.4 %
Zinc0.4 mg, 4 %
Vitamin B60.05 mg, 3.4 %
Phosphorus20.8 mg, 3 %
Chloride21.6 mg, 2.7 %
Calcium19.2 mg, 2.4 %
Vitamin A0.0184 mg, 2.3 %
Iron0.24 mg, 1.7 %
Magnesium6.4 mg, 1.7 %
Copper0.02 mg, 1.6 %
Riboflavin (vitamin B2)0.01 mg, 0.6 %
Vitamin Dnone recorded
Vitamin B12none recorded
Badges use the UK legal thresholds per 100 g: 15 % of the reference intake for “source of”, 30 % for “high in”.
What fennel doesn’t give you. And where to find it.
No recorded vitamin D or vitamin B12, and only 0.7 % of the riboflavin reference intake per 100 g.
Vitamin D
0mgin fennel
Find it inBloater, grilled500 % per 100 g
Vitamin B12
0mgin fennel
Find it inLiver, ox, raw4400 % per 100 g
Riboflavin (vitamin B2)
0.7%in fennel, per 100 g
Find it inLiver, lamb, fried404 % per 100 g
100 mgVitamin C, 125 %
0.075 mgSelenium, 136 %
0.00125 mgVitamin D, 25 %
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Fennel against other vegetables
Per 100 g, mushrooms (Jew's ear, tender, dried, raw) has the most potassium in this comparison, followed by patra leaves (raw).
860mg
680mg
540mg
440mg
250mg
110mg
Patra leaves, raw+240 mg
Rape leaves, raw+100 mg
Fennel, Florence, rawthis page
Cabbage, red, raw−190 mg
All values per 100 g, from the same dataset. Differences are against fennel.
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Questions about fennel
The questions people ask about fennel, answered from the dataset.
How many calories are in a portion of fennel?
A typical portion (80 g, one of your five a day) gives 10 kcal. Per 100 g the figure is 12 kcal.
Is fennel a source of potassium?
It is a source of potassium: 440 mg per 100 g, 22 % of the NRV, which passes the 15 % threshold for “source of” but not the 30 % needed for “high in”.
Which vitamins and minerals does fennel have most of?
By share of the daily reference intake: potassium (440 mg, 22 %), folate (0.042 mg, 21 %) and vitamin C (5 mg, 6.3 %) per 100 g.
Is fennel a good source of protein?
Fennel, Florence, raw has 0.9 g protein per 100 g, 21 % of the energy, which meets the UK threshold for “high protein”.
How these numbers were made
Every figure comes from the UK Composition of Foods Integrated Dataset (CoFID), 2021 edition, record 13-241, Fennel, Florence, raw, published by Public Health England under the Open Government Licence v3.0. Main data references: Reviewed 2013. IFR, The nutritional composition of retail vegetables in the UK, 1984-1987. Values are per 100 g of the edible part; a portion is 80 g, one of your five a day, the usual UK portion for vegetables. Edible proportion: 80 % of the weight as bought is eaten. Reference intakes follow Regulation (EU) 1169/2011 Annex XIII as retained in GB law; “source of”, “high in” and “low” follow Regulation (EC) 1924/2006, assessed per 100 g. Function lines are the authorised wording from the GB register of nutrition and health claims, credited to the nutrient. Energy is rounded to the whole kcal and kJ; other amounts to one decimal, or two below 1. A trace is shown as “trace” and never gets a figure or a badge; a nutrient never analysed is left off the page. We start from the dataset’s 2,887 records and keep 2,322: records weighed with bone, shell or skin, alcoholic drinks, infant foods, brand-named products, records with fewer than eight measured vitamins and minerals and near-identical variants are left out. Group context uses the 240 vegetables kept from the dataset; a rank counts only the foods with a measured figure for that nutrient. Food images are illustrations from Ingredient Atlas, released under CC0; they show the food, not the measured sample. Checked 5 October 2026. Contains public sector information licensed under the Open Government Licence v3.0.
More vegetables
From the same group, with calories per 100 g, and the foods with the most potassium.
More vegetables
- Radish leaves, raw33 kcal
- Sweet potato, raw87 kcal
- Agar, dried16 kcal
- Cabbage, green, boiled17 kcal
- Courgette, fried63 kcal
- Mango, unripe, green flesh, raw46 kcal
- All 240 vegetables
Most potassium
- Courgette, dried6104 mg
- Spinach, dried4350 mg
- Mushroom, dried3870 mg
- Chervil, dried4740 mg
- Coriander leaves, dried4470 mg
- Parsley, dried4090 mg
- Potassium guide