Reference table

Electrolytes in food: sodium, potassium, magnesium and calcium per serving

The short answer: a medium baked potato has about 930 mg of potassium, more than a banana (420 mg) or a cup of coconut water (400 mg). Pumpkin seeds lead on magnesium, calcium-set tofu and dairy on calcium, and broth, canned soup and tomato juice on sodium.[1] Plain water carries almost none of the four.

  • Rows 33
  • Source USDA FoodData Central
  • Updated
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A medium baked potato carries more than twice the potassium of a banana

Milligrams per typical serving. Select a column heading to sort. Swipe the table sideways for more columns.

Sodium, potassium, magnesium and calcium in milligrams per typical serving of common foods and drinks.
Serving
Tap water1 cup (8 fl oz), 237 g Drinks 1 cup (8 fl oz) 237 g 9 0 2 7 173647
Milk, 2%1 cup, 244 g Drinks 1 cup 244 g 115 342 27 293 171267
Soy milk, calcium-fortified1 cup, 243 g Drinks 1 cup 243 g 114 296 36 299 172456
Orange juice, chilled1 cup, 249 g Drinks 1 cup 249 g 5 443 27 27 169100
Coconut water, unsweetened1 cup, 245 g Drinks 1 cup 245 g 64 404 15 17 174831
Tomato juice, canned, salted1 cup, 243 g Drinks 1 cup 243 g 615 527 27 24 170458
Vegetable juice, canned1 cup, 253 g Drinks 1 cup 253 g 428 468 28 35 170063
Bouillon, made with water1 cup, 241 g Drinks 1 cup 241 g 966 14 5 14 172924
Chicken broth, reduced sodium1 cup, 240 g Drinks 1 cup 240 g 554 204 2 19 172888
Coffee, brewed1 cup (8 fl oz), 237 g Drinks 1 cup (8 fl oz) 237 g 5 116 7 5 171890
Black tea, brewed1 cup (8 fl oz), 237 g Drinks 1 cup (8 fl oz) 237 g 7 88 7 0 173227
Yogurt, plain, low-fat6 oz container, 170 g Dairy and soy 6 oz container 170 g 119 398 29 311 170886
Cheddar cheese1 oz, 28.4 g Dairy and soy 1 oz 28.4 g 185 22 8 201 173414
Tofu, firm, calcium-set1/4 block, 81 g Dairy and soy 1/4 block 81 g 11 192 47 553 172475
Banana1 medium, 118 g Fruit 1 medium 118 g 1 422 32 6 173944
Orange1 fruit, 131 g Fruit 1 fruit 131 g 0 237 13 52 169097
Cantaloupe1 cup cubes, 160 g Fruit 1 cup cubes 160 g 26 427 19 14 169092
Avocado1/2 avocado, 100.5 g Fruit 1/2 avocado 100.5 g 7 487 29 12 171705
Dried apricots1/4 cup halves, 32.5 g Fruit 1/4 cup halves 32.5 g 3 378 10 18 173941
Potato, baked, with skin1 medium, 173 g Vegetables 1 medium 173 g 17 926 48 26 170093
Sweet potato, baked1 medium, 114 g Vegetables 1 medium 114 g 41 542 31 43 168483
Spinach, cooked1/2 cup, 90 g Vegetables 1/2 cup 90 g 63 419 78 122 168463
Dill pickle1 small spear, 35 g Vegetables 1 small spear 35 g 283 41 2 20 168558
White beans, cooked1/2 cup, 89.5 g Beans and lentils 1/2 cup 89.5 g 5 502 56 81 175203
Lentils, cooked1/2 cup, 99 g Beans and lentils 1/2 cup 99 g 2 365 36 19 172421
Edamame, cooked1/2 cup, 77.5 g Beans and lentils 1/2 cup 77.5 g 5 338 50 49 168411
Almonds1 oz (23 almonds), 28.4 g Nuts and seeds 1 oz (23 almonds) 28.4 g 0 208 77 76 170567
Pumpkin seeds, hulled1 oz, 28.4 g Nuts and seeds 1 oz 28.4 g 2 229 168 13 170556
Peanut butter, salted2 tbsp, 32 g Nuts and seeds 2 tbsp 32 g 136 179 54 16 174266
Salmon, farmed, cooked3 oz, 85 g Fish 3 oz 85 g 52 326 26 13 175168
Saltine crackers5 crackers, 15 g Snacks and soup 5 crackers 15 g 141 23 3 3 172746
Chicken noodle soup, canned1 cup, 248 g Snacks and soup 1 cup 248 g 831 60 10 12 172909
Dark chocolate, 70–85%1 oz, 28.4 g Snacks and soup 1 oz 28.4 g 6 203 65 21 170273

Source: USDA FoodData Central, SR Legacy data (April 2018 release).[1] Values per 100 g are scaled to the serving shown and rounded. Each FDC id links to that food’s record.

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How this table was made

Every food value comes from USDA FoodData Central (FDC), SR Legacy data, the April 2018 final release of USDA’s Standard Reference database.[1] We took each food by its FDC id from FDC’s SR Legacy data download on October 27, 2026; values per 100 g are as published. Each row’s FDC id is in the table and in the CSV, so any number can be checked against its record.

How servings were chosen: we used the household measure FDC lists for that food (1 cup, 1 medium, 1 oz) wherever a common one exists. Where the usual serving is a fraction of an FDC measure, such as half a cup of beans or half an avocado, we took that fraction of FDC’s gram weight. The grams for every serving are shown. Drinks are 1 cup (8 fl oz).

Values are for the food as described (cooked, canned, raw) and are rounded: milligrams to whole numbers, grams to one decimal. A brand or recipe can differ, so for a packaged food the Nutrition Facts label on that package is the better number. This is general information, not medical advice.

For scale, the adult Adequate Intakes are 2,600 mg (women) and 3,400 mg (men) of potassium and 1,500 mg of sodium; the RDAs are 310 to 420 mg of magnesium and 1,000 to 1,200 mg of calcium. All are in the DRI table for adults.[2]

Frequently asked questions

Which foods have the most potassium per serving?

In this table: a medium baked potato (about 930 mg), a medium baked sweet potato (540 mg), tomato juice (530 mg), half a cup of white beans (500 mg) and half an avocado (490 mg). A medium banana has about 420 mg.[1]

Does water contain electrolytes?

Very little. A cup of tap water in FoodData Central has about 9 mg of sodium, 7 mg of calcium and 2 mg of magnesium, though tap water varies by source.[1]

Is coconut water high in electrolytes?

It has potassium: about 400 mg in a cup of unsweetened, ready-to-drink coconut water, close to a banana. It is low in sodium (about 60 mg) compared with broth or tomato juice.[1]

Which foods are high in sodium?

Broth and soup lead this table: a cup of bouillon made with water has about 970 mg and a cup of canned chicken noodle soup about 830 mg. Adults are advised to reduce intake if it is above 2,300 mg a day.[1][2]

What are good food sources of magnesium?

Seeds, nuts, beans and greens. An ounce of pumpkin seeds has about 170 mg, half a cup of cooked spinach about 80 mg and an ounce of almonds about 75 mg.[1]

Cite this table

APA

Zornava. (2026). Electrolytes in food: sodium, potassium, magnesium and calcium per serving [Data set]. Retrieved October 27, 2026, from https://zornava.com/pages/electrolytes-in-food

Plain text

Zornava, “Electrolytes in food: sodium, potassium, magnesium and calcium per serving,” zornava.com, updated October 27, 2026, https://zornava.com/pages/electrolytes-in-food (accessed October 27, 2026).

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References

  1. US Department of Agriculture, Agricultural Research Service. FoodData Central. USDA. (SR Legacy, April 2018 release; FDC ids per row in the table) fdc.nal.usda.gov. ↩︎
  2. National Academies of Sciences, Engineering, and Medicine. Dietary Reference Intakes for Sodium and Potassium. Summary, Tables S-1 and S-2. National Academies Press. 2019. nap.nationalacademies.org. doi: 10.17226/25353. ↩︎