What Is the Right Sodium-to-Potassium Ratio in an Electrolyte Drink?

There is no single right ratio, because the phrase hides two different questions. For a drink that replaces what you sweated out, sodium should lead by a wide margin — roughly what sweat itself contains, somewhere between two and eight parts sodium to one part potassium by weight. For your diet as a whole, the advice runs the other way: more potassium than sodium. Most of the confusion on the electrolyte shelf comes from mixing those two up.

That confusion is visible on the labels. Line up the popular drinks and the sodium-to-potassium ratio runs from five to one in one direction to seventy to one in the other. Here is which ratio fits which job, and where our own stick lands.

The shelf disagrees by more than a factor of a hundred

These are the ratios printed, in effect, on each label. The milligram figures behind them are in our bottled-drink table and the Liquid I.V. and LMNT comparison; here we only divide one number by the other.

Sources: Abbott's Pedialyte panel; LMNT's own explanation of its ratio; the WHO reduced-osmolarity formula, 75 mmol/L sodium and 20 mmol/L potassium; other figures from the labels cited in the two articles linked above. Ratios are ours, rounded.

From LMNT at the top to Prime at the bottom is a spread of roughly 350-fold. These are not variations on one recipe. They are answers to different questions, and the label rarely tells you which question it is answering.

Milligrams or molecules: half the disagreement is units

Labels list minerals in milligrams. Your body, and the research, counts them in millimoles — the number of ions. A potassium atom weighs about 1.7 times as much as a sodium atom (39 against 23), so 100mg of potassium is far fewer ions than 100mg of sodium.

Molar ratio: the ratio of ions rather than of weights. To convert a sodium-to-potassium ratio by weight into a molar one, multiply by 1.7. A drink that is 1 : 1 by weight on its label is about 1.7 : 1 in favour of sodium inside you.

So when a forum post recommends "a one-to-one ratio" and another says "three to two", it is worth asking which units they mean before deciding they disagree. Throughout this article, a ratio without a label means by weight, the way your packet reads.

What sweat actually takes, and in what proportion

The most defensible answer for a replacement drink is to put back roughly what left. That makes sweat the reference, and sweat is lopsided.

A 2019 review of sweat gland physiology in Temperature gives sweat sodium as roughly 10 to 90 mmol/L and sweat potassium as roughly 2 to 8 mmol/L. Sodium varies with how fast you sweat and with heat adaptation; potassium stays small whatever you do. How much sodium different people lose is a large subject of its own, and the long-day playbook walks through measuring your own.

Take illustrative mid-range values — 40 mmol of sodium and 5 of potassium in each litre — and sweat runs about 8 : 1 by ions, close to 5 : 1 by weight. The figure moves from person to person; the direction does not. You lose many times more sodium than potassium, so a replacement drink built on potassium is replacing the wrong mineral.

That is the whole case against the bottom of the table. Coconut water and the potassium-led bottles are not harmful, and a 700mg dose of potassium is a decent contribution to a day's food. It simply bears no resemblance to what a hard session takes out, a point the electrolytes explainer makes about the potassium myth in general.

The ratio for your diet runs the other way

Search for "sodium potassium ratio" and most results are about diet and blood pressure, saying what sounds like the opposite.

In the Trials of Hypertension Prevention follow-up, published in Archives of Internal Medicine in 2009, researchers measured sodium and potassium in repeated 24-hour urine collections and followed participants for 10 to 15 years. A higher sodium-to-potassium ratio was associated with more later cardiovascular disease, and the ratio predicted it better than either mineral alone. That is observational evidence, not a trial of changing the ratio, but it is consistent with the dietary guidance.

The World Health Organization recommends adults keep sodium below 2,000mg a day and take in at least 3,510mg of potassium. That works out to a daily ratio of about 1 : 1.75 in favour of potassium, roughly 1 : 1 by ions. Meanwhile the FDA reports that Americans eat about 3,400mg of sodium a day, and the NIH puts typical adult potassium intake from food at roughly 2,300 to 3,000mg. The average diet is upside down: too much sodium, not enough potassium.

Both pieces of advice are correct at once, because they describe different time scales:

• Across a whole day of eating, you want more potassium than sodium. That comes from vegetables, fruit, beans and potatoes, not from a drink.
• In the glass that replaces a sweat loss, you want more sodium than potassium, because that is what left.

A drink is a small slice of the day. Its ratio does not fix your diet's, and a good diet does not make a potassium-heavy bottle a rehydration drink.

Why so many powders stop at 99mg of potassium

Supplement labels cluster just under 100mg of potassium, and not for nutritional reasons. According to the NIH Office of Dietary Supplements, many makers stop at 99mg because of FDA concerns about potassium-containing drugs — chiefly that the agency ruled oral drug products with more than 99mg unsafe after potassium chloride tablets were linked to small-bowel lesions.

The same fact sheet lists who needs to be careful with added potassium at any dose: people with chronic kidney disease, and people taking ACE inhibitors, angiotensin receptor blockers or potassium-sparing diuretics. For most healthy people, potassium from a drink is harmless. For those groups, it is a question for their doctor, and the ratio on the label matters more than the marketing.

So what ratio should you look for?

Match the drink to the job rather than hunting for one perfect number.

• Replacing a real sweat loss — a long, hot session, a day outdoors, a heavy night. Sodium-led, somewhere from about 2 : 1 to 5 : 1 by weight, with real sodium in absolute terms. The ratio is meaningless if the sodium figure is tiny. Whether 1,000mg is too much depends on how much you lost, which the LMNT comparison works through.
• A stomach bug, or a morning when you are truly run down. The medical formula's ratio, about 2.2 : 1, with glucose alongside; the best-drink comparison explains why that benchmark exists.
• Every day, with no sweat to speak of. You probably do not need an electrolyte drink at all, and if you want one, keep the sodium modest. Your potassium target is met at the table.
• You have kidney disease or take blood-pressure medication. Ask before adding potassium or sodium in any ratio.

Frequently asked questions

What is the best sodium-to-potassium ratio for an electrolyte drink? For replacing sweat losses, sodium-led — roughly 2 : 1 to 5 : 1 by weight, which mirrors what sweat contains. The WHO's oral rehydration formula sits at about 2.2 : 1. Drinks that lead with potassium are not built for rehydration.

Should you have more potassium or more sodium? In your overall diet, more potassium: the WHO's targets imply about 1.75mg of potassium for every milligram of sodium. In a drink replacing sweat, more sodium, because sweat loses several times more sodium than potassium.

Is a 1:1 sodium-to-potassium ratio good? By weight, a 1 : 1 drink is about 1.7 : 1 by ions in favour of sodium — reasonable, though lower in sodium than sweat. As a daily diet target, 1 : 1 by ions is close to what the WHO's figures imply.

Is 1,000mg of sodium too much for an electrolyte drink? For a heavy sweater in heat, it can be a fair match. For someone at a desk, it is close to half the 2,300mg daily limit in one glass. The ratio does not change that; the absolute dose and your losses decide it.

Why is there so little potassium in electrolyte powders? Partly because sweat loses little of it, and partly because many supplement makers cap potassium at 99mg, under the threshold the FDA has applied to oral potassium drug products.

Is coconut water a good electrolyte drink? It is a good potassium drink. Its ratio runs roughly 1 : 13 against sodium, which is the reverse of what sweat loses, so it is a pleasant drink rather than a rehydration one.

Where Snake Oil fits

One stick in 16 ounces of water carries 370mg of sodium and 95mg of potassium, about 3.9 : 1 by weight and 6.6 : 1 by ions. That puts it between the WHO formula and a sports drink on the ratio scale, and close to the proportion an average litre of sweat carries. The potassium sits just under the 99mg line.

The sodium is paired with 5g of dextrose so it has a carrier into the gut, and the stick adds 30mg of magnesium, zinc, 200mg of vitamin C, vitamin E, seven B vitamins, a glutamine-led amino acid blend and 100mg of caffeine.† That is the reason it is built for one moment — the end of a long night or a long, sweaty day, when what you lost is mostly sodium and fluid — rather than as a potassium top-up for the diet. For the diet, eat the vegetables. For the glass after the sweat, the ratio should look like the sweat, and ours does.

†These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.

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Related reading: Best electrolyte drinks: ranked by what is actually in them · What are electrolytes? · The long-day playbook