How to convert table salt
Our reference is 288 grams per US reference cup of table salt, fine table salt, levelled; kosher and flaked salts weigh much less per spoon. That works out to about 1.2173 grams per millilitre, so cups = grams ÷ 288 and grams = cups × 288 in US customary measures.
For metric and Australian recipes the cup holds 250 ml, so one cup of table salt is about 304.33 grams. Australian tablespoons hold 20 ml rather than 15 ml, which the calculator handles when you pick that system.
Preparation changes the weight
The reference describes table salt as: fine table salt, levelled; kosher and flaked salts weigh much less per spoon. A different form, such as sifted, packed, melted, chopped or cooked, can hold a different weight in the same cup and needs its own reference. When a recipe gives a gram amount, weigh that amount instead of converting.
Brand, moisture and how firmly the cup is filled all move the practical result. Treat the numbers here as recipe equivalents, not laboratory densities.
Where the number comes from
The reference comes from King Arthur Baking ingredient weight chart, which lists 1 tablespoon as 18 grams. Published weight of 18 g per tablespoon of table salt, multiplied by 16 tablespoons per US cup. Diamond Crystal kosher salt is listed at 8 g and Morton kosher at 16 g per tablespoon on the same chart and are not interchangeable. This site assigns the published cup weight to its adopted US reference cup of 236.5882365 ml; the source itself does not define an exact millilitre cup volume. Checked September 26, 2026.