The serving size on a label is a measuring convention, not a suggestion

The Food and Drug Administration is clear that serving sizes on the Nutrition Facts label are not a recommendation of how much to eat. They reflect the amount people typically consume, and they are standardized so that similar products can be compared fairly.

Those standard amounts are set in federal regulation, which is why they look oddly specific. Salad dressing uses a reference amount of 30 grams, about 2 tablespoons. Mayonnaise and sandwich spreads use 15 grams, about 1 tablespoon. Salt and salt substitutes use a quarter teaspoon.

This matters because two sauces can both be accurate and still be impossible to compare at a glance. One lists a tablespoon, another lists 2 tablespoons, a third lists a quarter cup, and a jar imported for a different market may list 100 grams. The sodium numbers sit right next to each other in your memory and mean completely different things.

Before you compare anything, write down the serving size. Then convert.

Put every sauce on the same spoon

The arithmetic takes about a minute per bottle and you only have to do it once.

1. 1 Find the serving size and the sodium in milligrams on the Nutrition Facts panel.
2. 2 Convert the serving size to tablespoons. A quarter cup is 4 tablespoons. Two tablespoons is 2. A teaspoon is a third of a tablespoon, so multiply a per teaspoon number by 3.
3. 3 Divide the sodium by that number of tablespoons. Now you have milligrams per tablespoon, and every sauce in your kitchen speaks the same unit.
4. 4 Multiply by the number of tablespoons the recipe actually uses, then divide by the number of people the dish feeds.

Step 4 is the one most people skip, and it is the one that tells you something new.

Here is the arithmetic with invented numbers, so you can practice the method before you apply it to the labels in your own kitchen. These are not measured values for any real product. Use the numbers printed on the bottle in front of you.

At the tablespoon level, Sauce B looks like the worst offender and Sauce C looks harmless. Now cook with them.

The tablespoon sauce against the cup sauce

Suppose a weeknight stir fry for four people uses 2 tablespoons of Sauce A and 1 teaspoon of Sauce B. Using the made up numbers above, that is 2,000 mg plus 400 mg, or 2,400 mg for the pan, which is 600 mg per person.

Now suppose a braise for the same four people uses a cup and a half of Sauce C. That is 24 tablespoons at 120 mg, or 2,880 mg for the pot, which is 720 mg per person. The sauce with the smallest number per tablespoon contributed the most sodium to the meal.

This is the whole reason to compare at the dish level. Sauces used by the spoon are self limiting, because a recipe rarely calls for much. Sauces used by the cup, the ladle or the jar are the ones that quietly carry the load: braising liquids, curry bases, simmer sauces, stewed tomato sauces, gravies, mole, adobo cooking liquid, dressings poured rather than tossed.

Two honest adjustments make the estimate better.

1. 1 If part of the sauce is a marinade you drain off and discard, less of that sodium reaches the plate. How much less depends on how long the food sat in it and how much surface it had, so treat the full amount as the ceiling rather than the true figure.
2. 2 If the sauce goes on the table instead of into the pot, the number is whatever each person actually spoons out, which is usually far less than the recipe amount. Serving sauces separately is covered in a separate article in this series.

For context, the American Heart Association recommends no more than 2,300 mg of sodium a day, says an ideal limit for most adults is no more than 1,500 mg, and reports that Americans average more than 3,100 mg. More than 70 percent of that comes from packaged, prepared and restaurant food rather than from the shaker. One home cooked dish at 600 or 700 mg per person is not a disaster. It is a number worth knowing, because it shows you where the room is.

What the words on the front of the bottle actually promise

Front label claims are defined in regulation, and the definitions are narrower than they sound. FDA sets these meanings for a labeled serving:

1. 1 Sodium free means less than 5 mg per serving.
2. 2 Very low sodium means 35 mg or less per serving.
3. 3 Low sodium means 140 mg or less per serving.
4. 4 Reduced sodium means at least 25 percent less than the regular version of that same product.
5. 5 Light in sodium means at least 50 percent less than the regular version.
6. 6 No salt added or unsalted means no salt was added during processing, which is not the same as containing no sodium.

The fourth one causes the most confusion in a sauce aisle. Reduced sodium is measured against the same maker's regular product, not against any general standard. A reduced sodium version of a very salty fermented sauce can still be one of the saltiest things in your kitchen, and it can still be a sensible swap if you use the same amount you always did. Both things are true at once.

FDA also gives a quick rule for the percent Daily Value column: 5 percent or less per serving is low, and 20 percent or more is high. That rule is genuinely useful, as long as you remember it refers to the label's serving size, not to the amount you cook with. A quarter cup at 20 percent becomes 60 percent if you pour three quarters of a cup.

One more reason to recheck bottles you have bought for years: recipes on the manufacturing side are changing. FDA finalized voluntary sodium reduction targets for packaged and restaurant foods in October 2021 and issued a second round in draft form on August 15, 2024, covering 163 food categories that include sauces, condiments and dressings. The agency's stated aim for the second phase is to bring average intake down to roughly 2,750 mg a day. A sauce you compared three years ago may carry a different number now.

When the label is not in english

Plenty of the best sauces in an American kitchen come from shelves where the packaging was designed for somewhere else. The rules here are more helpful than most people expect.

Under federal labeling regulation, required label information must appear in English for food sold in the United States, with an exception for products distributed solely in Puerto Rico or a territory where the predominant language is not English. If a label carries any representation in a foreign language, all the required statements must also appear in that language. In practice this means a product legally sold at a US grocery store should carry a Nutrition Facts panel and an ingredient list you can read, sometimes as a sticker applied over the original panel. Lift the corner if you need to.

When the panel is metric or the only numbers you can find are per 100 grams, you can still compare. A tablespoon of a thin, pourable sauce weighs roughly 15 to 18 grams, so dividing a per 100 gram figure by about 6 gives a workable per tablespoon estimate. Thick pastes are denser and a tablespoon weighs more, so that estimate runs low for them. It is close enough to rank your bottles, which is all you need.

A few habits make unfamiliar labels readable:

1. 1 Learn to spot the word for salt. Common ones include sal in Spanish and Portuguese, sale in Italian, sel in French, Salz in German, 塩 in Japanese, 鹽 or 盐 in Chinese, 소금 in Korean, muối in Vietnamese, เกลือ in Thai, and namak in Hindi and Urdu.
2. 2 Ingredient lists run in order of weight, most first. If salt sits in the first three ingredients, the product is salty regardless of what the front says.
3. 3 Sodium travels under other names. Anything beginning with sodium contributes it, including monosodium glutamate, sodium bicarbonate, sodium benzoate, sodium nitrite and disodium phosphate. Fermented pastes, brines, cured fish and shellfish products, bouillon and stock concentrates, and seasoning mixes all carry salt whether or not the word appears prominently.
4. 4 Look for the sodium line by shape rather than by word. It is the row with a number followed by mg and a percentage, usually the fourth or fifth line down the panel.
5. 5 If a jar truly has no Nutrition Facts panel, you are probably holding something imported outside normal retail channels. Judge it from the ingredient list and treat it as salty if salt or a salted ingredient appears early.

Translation apps handle printed ingredient lists reasonably well through a phone camera, and they are more reliable for a short ingredient list than for marketing text.

Some reduced sodium sauces swap in potassium

To cut sodium while keeping a salty taste, some products replace part of the sodium chloride with potassium chloride. On an ingredient list this may appear as potassium chloride or as potassium salt. FDA issued final guidance in December 2020 allowing potassium salt as an alternate name, so both phrases mean the same ingredient.

For most people this is not something to think about. For some people it is. The National Institute of Diabetes and Digestive and Kidney Diseases advises people with chronic kidney disease to use herbs and spices rather than salt substitutes, and to limit foods that list potassium chloride in the ingredients, because the kidneys control how much potassium leaves the body. Certain blood pressure and heart medicines also raise blood potassium.

If you have reduced kidney function or take medicines that affect potassium, ask your health care professional or pharmacist before you build your cooking around reduced sodium products, and ask whether your blood potassium should be checked. A separate article in this series covers the questions worth asking about potassium based salt substitutes. Nobody can answer that one from a label.

One week of measuring tells you more than any chart

Guessing at sauce volumes is where these estimates fall apart. For one week, use measuring spoons instead of pouring, and write the amount on the recipe card or in your phone. Most people find they use more than they thought of the sauce they reach for automatically and less of the one they consider strong.

At the end of the week you will have a short ranked list of which bottles contribute most in your actual cooking. Work on the top of that list. Cutting a third out of the sauce you use by the cup does more than eliminating a sauce you use by the teaspoon, and it usually costs less flavor, because the intense sauces are often the ones carrying the dish's identity.

Cutting the number without losing the dish

Once you know which sauce is doing the damage, the fixes are ordinary kitchen moves.

1. 1 Dilute the heavy hitter. Stretch a braising or simmer sauce with unsalted stock, water, tomato, coconut milk, or the cooking liquid from beans you cooked yourself, then bring the flavor back up with acid and aromatics.
2. 2 Blend the regular and lower sodium versions. The American Heart Association suggests combining lower sodium and regular versions of a food in equal parts and adjusting from there, which works well for soy sauce, broth and canned tomatoes and avoids the flat taste of an abrupt switch.
3. 3 Move the salty sauce to the end. Used as a finishing drizzle where you taste it directly, a strong sauce goes further than the same amount stirred into a pot early, where it disappears into the whole volume.
4. 4 Build the background with things that are not salty. The American Heart Association names onions, garlic, herbs, spices, citrus juices and vinegars as flavor builders in place of salt, and points to grilling, braising, roasting, searing and sautéing to bring out the flavor already in the food. Toasting whole spices, browning aromatics properly and finishing with fresh herbs or a squeeze of lime all do work that salt would otherwise have to do.
5. 5 Drain and rinse canned beans and vegetables before they go into a sauced dish, another American Heart Association suggestion, so the sauce is not competing with sodium you did not account for.
6. 6 Taste before you add anything. The Association's simplest advice is to taste food before reaching for salt, which applies just as much to the second splash of fish sauce as to the shaker.

Taste preferences do shift with what you eat. In a five month feeding study published in 1982, young adults who ate less sodium came to prefer less salt in soup and crackers, while a comparison group who ate normally did not change. The Association puts it plainly, saying it may take some time for your taste buds to adjust. A dish that tastes underseasoned the first week often tastes right later.

Pick your next familiar meal, measure the sauces as you cook it, and run the numbers once. One dish is enough to show you where your sodium actually lives.