How much potassium is in canned tuna?
Canned tuna has 201 mg of potassium per 3 oz drained (85 g) — about 4% of the 4,700 mg Daily Value. That's 237 mg per 100 g, roughly 0.5× a medium banana (~422 mg).
USDA FoodData Central · light, canned in water, drained · FDC 171986
Potassium by portion
| Portion | Potassium | % DV | Sodium | Calories |
|---|---|---|---|---|
| 3 oz drained (85 g) | 201 mg | 4% | 43 mg | 99 |
| 100 g | 237 mg | 5% | 50 mg | 116 |
| 1 oz (28 g) | 67 mg | 1% | 14 mg | 33 |
% DV against the FDA Daily Value of 4,700 mg of potassium. Whole foods are naturally potassium-rich and low in sodium — the ratio heart guidelines (like DASH) favor. Values from USDA per-100 g data (FDC 171986, SR Legacy). light, canned in water, drained.
Canned tuna is known for protein, not potassium — and the numbers bear that out. A 3 oz drained serving (85 g) carries about 201 mg of potassium, which is 237 mg per 100 g and roughly 4% of the 4,700 mg Daily Value. That’s a real but modest amount: tuna won’t move the needle toward your potassium target the way a baked potato or a banana does. What makes the potassium worth noting is the company it keeps — it rides along with about 22 g of protein in that same lean, low-calorie serving, so you’re getting a small potassium bonus from a food you’re eating for other reasons.
Why potassium matters — and where tuna fits
Potassium is the blood-pressure mineral. It works as the counterweight to sodium, helping the kidneys flush excess sodium and relaxing the walls of your blood vessels, which is why potassium-rich, lower-sodium eating patterns like DASH are tied to healthier blood pressure. It also keeps fluid balance steady, carries nerve signals, and powers muscle contraction. The practical problem for most people isn’t too much potassium — it’s not enough, since diets tend to run high in sodium and well below the 4,700 mg goal. Tuna helps on the sodium side of that ratio: the USDA reference here is for tuna canned without added salt, which is naturally low in sodium while supplying its ~201 mg of potassium. Most supermarket cans add salt, which raises sodium without changing the potassium — worth knowing if you’re watching that balance.
A protein food that carries a little potassium
The honest framing is that tuna is a protein food that brings some potassium, not a potassium source you’d build a day around. Set it against the field and the gap is clear: a medium banana (~422 mg) more than doubles tuna’s serving, and a baked potato (~951 mg) dwarfs it. Even salmon (~326 mg per 3 oz) — the other canned-and-fresh fish people reach for — carries noticeably more. So lean on potatoes, beans, leafy greens, and fruit to actually hit 4,700 mg, and count tuna’s ~201 mg as a useful add-on that comes free with the protein. One brief, non-medical note: people with kidney disease are sometimes advised to limit potassium, so this is reference data rather than medical advice.
For the side of tuna that actually makes it a staple — the protein — see protein in canned tuna.
Packaged canned tuna options, graded
Prefer something off the shelf? Here are the best-graded canned tuna in our catalog — each scored on our transparent Labelgrade.
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Labelgrade 83/100 · 24 g protein
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Labelgrade 80/100 · 11 g protein
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Labelgrade 79/100 · 13 g protein
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Frequently Asked Questions
How much potassium is in a 3 oz serving of canned tuna?
About 201 mg of potassium in a 3 oz drained serving (85 g), which is 237 mg per 100 g (USDA FDC 171986). That's a modest amount — roughly 4% of the Daily Value — that comes along with about 22 g of protein in the same serving.
What percent of the daily value for potassium is in canned tuna?
About 4% of the 4,700 mg FDA Daily Value from a 3 oz drained serving (~201 mg). Tuna isn't a potassium powerhouse like a potato or a banana; it's a high-protein food that carries a little potassium, so treat it as a small contributor rather than a primary source.
How does canned tuna's potassium compare to a banana?
A banana wins on potassium. A 3 oz serving of tuna has about 201 mg versus roughly 422 mg in a medium banana, so tuna delivers under half a banana's potassium. Where tuna pulls ahead is protein — about 22 g per serving against a banana's ~1.3 g — so they're useful for different reasons.
Does canned tuna have more or less potassium than salmon?
Less. A 3 oz serving of cooked salmon carries roughly 326 mg of potassium against tuna's ~201 mg. Both are lean, low-sodium proteins, but salmon brings more potassium and omega-3 fats, while tuna is cheaper and shelf-stable (USDA FDC 171986 for tuna).
Why does potassium matter, and is tuna a good way to get it?
Potassium helps regulate blood pressure by balancing sodium and relaxing blood vessel walls, and supports fluid balance, nerve signaling, and muscle function. Most people fall short of the 4,700 mg target. Tuna helps a little — about 201 mg per serving with naturally low sodium in the no-salt-added reference — but you'll reach the target faster with potatoes, beans, leafy greens, and fruit. This is general nutrition information, not medical advice.
When was this data last verified?
2026-06-18, against USDA FoodData Central FDC 171986 (Fish, tuna, light, canned in water, drained; SR Legacy). We re-verify reference pages periodically and update when USDA revises the entry.
Whole-food values are USDA reference data, not a Labelgrade (that score is for branded packaged products). High-potassium diets aren't for everyone — people with kidney disease are often told to limit it; this is reference data, not medical advice. See our methodology.