Garlic Salt is a flavoured salt mix made and sold commercially. It is regular table salt mixed with garlic powder, in a ratio of 1 part garlic powder to 3 parts regular table salt. Many of the mixes also have calcium silicate added to keep them free flowing from the glass shaker bottles they are usually sold in.
Some variations are flavoured with lime.
Garlic Salt is used as a seaoning in cooking to add a pronounced garlic flavour; it is almost never used at the table.
Cooking Tips
To make your own, mix up to 1 part garlic powder with 3 parts regular table salt. Shake to mix. Or, make “fresh garlic” salt, mash 1 peeled garlic clove with 1 teaspoon of regular table salt.
Substitutes
For every clove of fresh garlic in a recipe, you can use 1/2 teaspoon of garlic salt. Hold back on any other salt in the recipe, then add only what plain salt you think is necessary for taste afterward.
OR just use fresh garlic and regular salt in quantities to taste.