Salt to Sodium Calculator

How salt-to-sodium conversion works

Table salt is a crystal made of sodium and chlorine (NaCl). Under 21 CFR 101.61(c), the FDA rule states: "The term "salt" is not synonymous with "sodium." Salt refers to sodium chloride." By weight, sodium makes up nearly two-fifths of the crystal, while chloride makes up the rest.

In USDA FoodData Central (FDC ID 173468, NDB 2047, Salt, table), 100 grams of salt holds 38,800 mg of sodium on the portal. That equals 388 mg per gram, or 38.8% by weight. The USDA API lists the same record at 38,758 mg per 100 grams (387.58 mg/g, or 38.758%). Both sit a little below the 393.39 mg per gram of pure sodium chloride worked out below. This page uses the portal's 388.

That USDA record also sets the kitchen weights for table salt. One dash weighs 0.4 g, one teaspoon 6 g, one tablespoon 18 g and one cup 292 g. The household measures table below works each of those weights out in milligrams of sodium at 388 mg per gram. A teaspoon of kosher salt holds less than 6 g. Enter kosher salt in grams, or compare spoons in the spoon table below.

To check a recipe or food box, divide total sodium by the number of servings. Next, compare each serving with the 2,300 mg adult Daily Value in 21 CFR 101.9(c)(9). For children ages 1 to 3, the Daily Value is 1,500 mg. A Daily Value is a label reference, not a personal limit. The page also applies the 0 mg, 5 mg, and 10 mg label steps in 21 CFR 101.9(c)(4). It reads the FDA's guide to %DV too. You can resize your batch in the recipe scaling calculator or swap cans in the can size conversion calculator.

Conversion and label rounding formulas

salt (g) = salt × 6 (for tsp) | salt × 18 (for tbsp) | salt (for g)
sodium (mg) = salt (g) × 388   [USDA FDC 173468 portal: 38,800 mg per 100 g]
SR Legacy sodium (mg) = salt (g) × 387.58   [FDC 173468 unrounded: 38,758 mg per 100 g]
pure NaCl sodium (mg) = salt (g) × (22.98976928 ÷ 58.43976928) × 1,000 = salt (g) × 393.3925
salt (g) = sodium (mg) ÷ 388;   salt (tsp) = salt (g) ÷ 6;   salt (tbsp) = salt (g) ÷ 18
sodium per serving (mg) = sodium (mg) ÷ servings
%DV (adult, >= 4 yr) = sodium per serving ÷ 2,300 × 100;   %DV (child 1–3 yr) = sodium per serving ÷ 1,500 × 100
21 CFR 101.9(c)(4) label sodium = 0 mg (< 5 mg) | nearest 5 mg (5–140 mg) | nearest 10 mg (> 140 mg)

Worked salt and sodium examples

Default soup pot (1 tsp table salt across 4 servings). One level teaspoon of table salt weighs 6 g (0.33 tbsp). Divided across 4 servings, each bowl gets 582 mg of sodium. That equals 25.3% of the 2,300 mg adult Daily Value (and 38.8% of the 1,500 mg child Daily Value). Under 21 CFR 101.9(c)(4), a food label rounds that serving to the nearest 10 mg step as 580 mg.

Reverse lookup from a food label (500 mg sodium in 1 serving). Suppose a bowl of canned soup lists 500 mg of sodium per serving. Dividing 500 mg by 388 mg/g gives 1.289 g of table salt (1.29 g on the card). Dividing 1.289 g by 6 g per teaspoon gives 0.21 tsp (or 0.07 tbsp). At 1 serving, 500 mg is 21.7% of the 2,300 mg Daily Value (22% whole-percent label DV). That is above the 460 mg (20% DV) mark the FDA guide calls high.

Bread loaf batch (10 g salt across 8 slices). A bread formula with 10 g of fine salt (1.67 tsp or 0.56 tbsp) holds 3,880 mg of sodium. That compares with 3,876 mg in SR Legacy and 3,934 mg in pure NaCl. Sliced into 8 servings, each slice holds 485 mg of exact sodium (21.1% DV), which rounds to 490 mg on a label. Measuring that same 10 g by volume takes 2.08 tsp of Morton Coarse Kosher or 3.57 tsp of Diamond Crystal Kosher.

Assumptions and limitations

• The main factor (388 mg per gram) and spoon weights (6 g per tsp, 18 g per tbsp) come from USDA FoodData Central. Unrounded SR Legacy, NIST pure NaCl, and the CDC guide appear beside it in the first table.
• Teaspoon and tablespoon inputs assume fine table salt at 6 g per teaspoon. A spoon of kosher salt weighs less, so enter its weight in grams; the spoon table compares table salt, Morton and Diamond Crystal. The kosher rows use the 400 mg per gram their labels work out to, the table salt row the USDA 388 mg per gram. There is no sea salt figure on this page.
• Daily Value shares use the 2,300 mg label reference in 21 CFR 101.9(c)(9) for ages 4 and up. Ages 1 to 3 use 1,500 mg. These are label references, not personal limits. The Daily Value question below gives the Dietary Guidelines figure.
• Only the salt or sodium amount entered is converted. In a full dish, broth, cheese, soy sauce, cured meats, and baking soda also add sodium.

What to do with your sodium result

If per-serving sodium reaches 460 mg or more (20% DV, which the FDA guide calls high), try less added salt and taste. Dropping 1 tsp across 4 servings to 0.75 tsp cuts sodium to 437 mg (19.0% DV). At 0.5 tsp it is 291 mg (12.7% DV). Then check your day's share in the Daily Value tool.

When a recipe lists kosher salt in spoons, check the spoon table or the salt converter. Across 4 servings, 1 teaspoon of Diamond Crystal adds 280 mg of sodium per serving (12.2% DV) on its label basis. By contrast, 1 teaspoon of Morton Coarse Kosher adds 480 mg per serving (20.9% DV).

When building a package panel, use the 21 CFR 101.9(c)(4) label sodium figure in the work lines. For example, 72.75 mg per serving (from 1/8 tsp across 4 servings) rounds to 75 mg on the label. At 1/4 tsp across 4 servings, 145.5 mg rounds to 150 mg. Check full recipe panels in the label rounding tool and portion tool.

When scaling a soup, sauce, or dough batch, pair this page with the recipe scaler and can size converter. Check the can or carton as well: the FDA guide says a low sodium claim means 140 mg or less per serving.

Salt and sodium questions