51 %
Potassium contributes to normal functioning of the nervous system and to normal muscle function.
How many calories are in microwaved old potatoes?
161kcal
in a 175 g portion
92 kcal per 100 g.
Source: UK CoFID 2021, record 13-494, 11 analysed samples. Checked 5 October 2026.
0.18 gFat
4.6 gProtein
4.7 gFibre
51 %Daily potassium
What’s in a 175 g portion
More than half of a portion is water, which is why the calories stay low. What is left is mostly carbohydrate.
- 0.18 gFat
- 4.6 gProtein
- 37.6 gCarbohydrate
- 4.7 gFibre
- 128 gWater
Below average for potatoes
Old potatoes are 92 kcal per 100 g. The 37 potatoes in this database average 179.
Old potatoes92
Potatoes average179
Low in sugar, almost no salt
Low sugars and very low salt by UK labelling rules, per 100 g.
Sugars, per portion3.7 g
Salt, per portion0.01 g
Vitamins and minerals in old potatoes
Four of the 21 reach the “source of” level, potassium first; none reaches “high in”.
Only a trace
- Vitamin A
- Selenium
None recorded
- Vitamin D
- Vitamin B12
Show all 21 with amounts
Potassium1024 mg, 51 %
Thiamin (vitamin B1)0.4 mg, 37 %
Folate0.0578 mg, 29 %
Chloride212 mg, 26 %
Vitamin B60.25 mg, 18 %
Copper0.16 mg, 16 %
Manganese0.32 mg, 16 %
Pantothenic acid (vitamin B5)0.84 mg, 14 %
Niacin (vitamin B3)2.1 mg, 13 %
Magnesium47.3 mg, 13 %
Vitamin C8.8 mg, 11 %
Phosphorus75.3 mg, 11 %
Iron1.3 mg, 9.4 %
Zinc0.7 mg, 7 %
Calcium22.8 mg, 2.8 %
Vitamin E0.23 mg, 1.9 %
Riboflavin (vitamin B2)0.02 mg, 1.3 %
Iodine0.00175 mg, 1.2 %
Biotin0.000525 mg, 1.1 %
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”. A trace is shown as “trace” and never counts.
What old potatoes don’t give you. And where to find it.
No recorded vitamin D or selenium, and only 4 % of the zinc reference intake per 100 g.
Vitamin D
0mgin old potatoes
Find it inBloater, grilled500 % per 100 g
Selenium
Tracein old potatoes
Find it inKidney, pig, fried491 % per 100 g
Zinc
4%in old potatoes, per 100 g
Find it inOysters, raw592 % per 100 g
100 mgVitamin C, 125 %
0.075 mgSelenium, 136 %
0.00125 mgVitamin D, 25 %
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Old potatoes against other potatoes
Old potatoes come second for potassium here, just behind potato chips (fine cut, frozen, fried in blended vegetable oil).
720mg
585mg
360mg
320mg
300mg
Potatoes, old, microwaved, flesh and skinthis page
Potato croquettes, fried−225 mg
Potatoes, new and salad, raw−265 mg
All values per 100 g, from the same dataset. Differences are against old potatoes.
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Questions about old potatoes
What the numbers say to the questions people actually search.
How many calories are in a portion of old potatoes?
A typical portion (175 g, a medium portion) gives 161 kcal. Per 100 g the figure is 92 kcal.
Is old potatoes a source of potassium?
It is a source of potassium: 585 mg per 100 g, 29 % of the NRV, which passes the 15 % threshold for “source of” but not the 30 % needed for “high in”.
Does cooking change the folate in old potatoes?
Yes. Per 100 g, folate goes from 13 mg raw to 0.033 mg microwaved. Part of that is the vitamin or mineral itself changing, part is the change in water content.
Which vitamins and minerals do old potatoes have most of?
By share of the daily reference intake: potassium (585 mg, 29 %), thiamin (0.23 mg, 21 %) and folate (0.033 mg, 17 %) per 100 g.
How these numbers were made
Every figure comes from the UK Composition of Foods Integrated Dataset (CoFID), 2021 edition, record 13-494, Potatoes, old, microwaved, flesh and skin, 11 analysed samples, published by Public Health England under the Open Government Licence v3.0. Main data references: DH, Nutrient analysis of fruit and vegetables, 2013. Values are per 100 g of the edible part; a portion is 175 g, a medium portion, the usual UK portion for potatoes. 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 37 potatoes 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: Potato). Checked 5 October 2026. Contains public sector information licensed under the Open Government Licence v3.0.
More potatoes
From the same group, with calories per 100 g, and the foods with the most potassium.
More potatoes
- Potato chips, fine cut, frozen, fried in blended vegetable oil364 kcal
- Potato chips, fried in dripping197 kcal
- Potato chips, straight cut, frozen, fried273 kcal
- Potato powder, instant, made up with water57 kcal
- Potatoes, old, mashed with butter102 kcal
- Potato chips, crinkle cut, frozen, fried290 kcal
- All 37 potatoes