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How many calories are in boiled fennel?

8.8kcal

in an 80 g portion

11 kcal per 100 g.

Source: UK CoFID 2021, record 13-542. Checked 5 October 2026.

0.16 gFat

0.72 gProtein

1.8 gFibre

12 %Daily potassium

Fennel, Florence, boiled in unsalted water

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
  • 1.2 gCarbohydrate
  • 1.8 gFibre
  • 75.5 gWater
  • 0.6 gMinerals and the rest

Below average for vegetables

Fennel is 11 kcal per 100 g. The 240 vegetables in this database average 59.9.

Fennel11
Vegetables average59.9

Low in sugar, almost no salt

Low sugars and very low salt by UK labelling rules, per 100 g.

Sugars, per portion1.1 g
Salt, per portion0.02 g

Vitamins and minerals in fennel

One of the 17 reach the “source of” level, potassium first; none reaches “high in”.

12 %

Potassium

240 mg in an 80 g portion

109th of 240 vegetables

Potassium contributes to normal functioning of the nervous system and to normal muscle function.

Folate0.0208 mg10 %
Vitamin K0.00392 mg5.2 %
Vitamin B60.06 mg4.6 %
Zinc0.32 mg3.2 %

None recorded

  • Vitamin D
  • Vitamin B12
Show all 17 with amounts
Potassium240 mg, 12 %
Folate0.0208 mg, 10 %
Vitamin K0.00392 mg, 5.2 %
Vitamin B60.06 mg, 4.6 %
Thiamin (vitamin B1)0.04 mg, 3.6 %
Zinc0.32 mg, 3.2 %
Chloride21.6 mg, 2.7 %
Phosphorus16.8 mg, 2.4 %
Vitamin C1.6 mg, 2 %
Calcium16 mg, 2 %
Magnesium5.6 mg, 1.5 %
Iron0.16 mg, 1.1 %
Vitamin A0.008 mg, 1 %
Copper0.01 mg, 0.8 %
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, and only 2.5 % of the vitamin C reference intake and 4 % of the zinc reference intake per 100 g.

Zinc

4%in fennel, per 100 g
Find it inOysters, raw592 % per 100 g
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0.075 mgSelenium, 136 %

0.00125 mgVitamin D, 25 %

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Free standard delivery to UK addresses. Royal Mail 48 tracked, usually 2 to 3 working days.

Made in Cambridgeshire

Made in the UK since 1998, with every nutrient and its declared amount listed on the label.

Fennel against other vegetables

Per 100 g, peas (dried, raw) has the most potassium in this comparison, followed by amaranth leaves (boiled).

Peas, dried, raw+690 mg
Amaranth leaves, boiled+240 mg
Okra, stir-fried+180 mg
Seaweed, kombu, dried, raw+150 mg
Fennel, Florence, boiled in unsalted waterthis page
Onions, boiled−195 mg

All values per 100 g, from the same dataset. Differences are against fennel.

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Questions about fennel

What the numbers say to the questions people actually search.

How many calories are in a portion of fennel?
A typical portion (80 g, one of your five a day) gives 9 kcal. Per 100 g the figure is 11 kcal.
Is fennel a source of potassium?
It is a source of potassium: 300 mg per 100 g, 15 % of the NRV, which passes the 15 % threshold for “source of” but not the 30 % needed for “high in”.
Does boiling change the vitamin C in fennel?
Yes. Per 100 g, vitamin C goes from 5 mg raw to 2 mg boiled. Part of that is the vitamin or mineral itself changing, part is the change in water content.
Which vitamins and minerals does fennel have most of?
By share of the daily reference intake: potassium (300 mg, 15 %), folate (0.026 mg, 13 %) and vitamin K (0.0049 mg, 6.5 %) per 100 g.
How these numbers were made
Every figure comes from the UK Composition of Foods Integrated Dataset (CoFID), 2021 edition, record 13-542, Fennel, Florence, boiled in unsalted water, 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. 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, and where no illustration of the exact food exists the nearest one is shown (here: Bulb Fennel). Checked 5 October 2026. Contains public sector information licensed under the Open Government Licence v3.0.

Nutrition

Fennel, Florence, boiled in unsalted water

Calories8.8 kcal
Fat
0.16 g
Carbohydrate
1.2 g
of which sugars
1.1 g
of which starch
0.08 g
Fibre
1.8 g
Protein
0.72 g
Salt
0.02 g

Vitamins and minerals

Potassium
240 mg
Folate
0.0208 mg
Vitamin K
0.00392 mg

37.6 kJ per portion. Values for the edible portion. Fibre measured by the NSP method. Source: UK CoFID 2021.

All 17 vitamins and minerals