Sodium vs salt: what the numbers mean

Sodium vs salt is a comparison of an element with a compound: they aren't the same thing. Table salt is sodium chloride, and sodium makes up only about 40% of its weight by mass. So "2,300mg of sodium" and "a teaspoon of salt" describe roughly the same amount — but they are not interchangeable numbers, and mixing them up leads to real math errors.

Sodium vs salt: what each word actually means

Salt, chemically, is sodium chloride (NaCl) — one sodium atom bonded to one chlorine atom. By weight, sodium accounts for about 40% of salt, and chloride makes up the other 60%. When someone says "cut back on salt," they usually mean cut back on sodium, since salt is the main source of sodium in most diets. But the two words aren't synonyms, and using them loosely is exactly where the confusion starts.

This distinction matters because "salt" is a household measurement — teaspoons, pinches, shakes — while "sodium" is a nutrition-label measurement, given in milligrams. They're two different units describing overlapping but not identical things, and a recipe that calls for "a teaspoon of salt" isn't telling you the sodium number directly.

Why nutrition labels list sodium, not salt

Every Nutrition Facts label in the U.S. reports sodium in milligrams, never salt in teaspoons or grams. That's the FDA's format, and it's consistent across every packaged food you'll ever check.

There's a practical reason for this. Food doesn't only get its sodium from added table salt — sodium also comes from preservatives like sodium benzoate, flavor enhancers like MSG (monosodium glutamate), leavening agents like baking soda (sodium bicarbonate), and naturally occurring sodium in some vegetables and dairy. Listing "salt" on the label wouldn't capture any of that. Listing sodium in milligrams captures all sodium sources in one consistent number, regardless of which compound it came from.

This is also why you can't reliably eyeball a food's sodium level from how salty it tastes, or from how much visible salt you see. A cracker seasoned with monosodium glutamate can carry meaningful sodium without a grain of visible salt on it.

The salt-to-sodium conversion, and why it trips people up

Because sodium is about 40% of salt's weight, converting between the two isn't a clean 1-to-1 swap. As a rough rule: 1 gram of salt contains about 400mg of sodium, and 1 teaspoon of salt (about 6 grams) contains roughly 2,300mg of sodium — which happens to line up almost exactly with the FDA's Daily Value.

That near-match between "1 teaspoon of salt" and "2,300mg of sodium" is a useful coincidence, but it's also where a lot of confusion creeps in. If a recipe or an old-style guideline tells you to keep salt under a certain number of grams, and you're tracking sodium in milligrams, you have to actually do the conversion — you can't compare the two numbers directly without it. Multiply grams of salt by roughly 0.4 to get milligrams of sodium; divide milligrams of sodium by roughly 400 to get grams of salt.

If terms like "Daily Value" and how the 2,300mg figure was set aren't familiar, what counts as a healthy daily sodium intake covers where that number comes from and how the FDA and AHA guidance differ.

Doing the math without doing the math

In practice, almost nobody wants to multiply by 0.4 every time they read a label or plan a meal — and you shouldn't have to. Sodium Tracker is an iPhone app that logs food against a daily sodium limit set from FDA, AHA, and WHO guidance, with barcode, photo, or voice logging and a library of high-sodium foods. It records the day against a chosen limit without requiring repeated kitchen arithmetic.

FAQ

Is salt the same as sodium?

No. Salt is sodium chloride, a compound that's roughly 40% sodium and 60% chloride by weight. Sodium is one specific element within salt, and it's also present in other compounds found in food, like MSG and baking soda, that don't taste salty at all.

How much sodium is in a teaspoon of salt?

About 2,300mg. A teaspoon of table salt weighs roughly 6 grams, and since sodium makes up about 40% of salt's weight, that works out to close to 2,300mg of sodium — which is also the FDA's Daily Value for sodium.

Why do nutrition labels show sodium instead of salt?

Because sodium comes from more than just added table salt — preservatives, flavor enhancers like MSG, and leavening agents like baking soda all contribute sodium without being "salt" in the culinary sense. Reporting sodium in milligrams captures all of these sources in one consistent number.

How do I convert grams of salt to milligrams of sodium?

Multiply the grams of salt by about 0.4 to get milligrams of sodium. To go the other direction, divide milligrams of sodium by about 400 to get grams of salt. It's an approximation, since exact ratios vary slightly by product, but it's close enough for everyday use.