Note: 1) observe an example using different salts in a recipe , 2) the bottom-right post-it explains that if someone knows the amount of Diamond kosher salt, then someone can multiply the amount by a percentage in the table to know how much salt of a different type to use, 3) table salt is about 1/2 the amount of Diamond kosher salt, use about twice as much Diamond kosher salt than table salt, 4) if a recipe uses table salt, double the amount to know the amount of Diamond kosher salt to use, then use the chart to find the amounts for other types of salt, 5) there is a sample for doing math with fractions below, and I have a blog post that has examples for working with approximations using fractions
Thomas Keller says in his cookbook ad hoc at home that he usually uses Diamond Kosher Salt. The density of Diamond Kosher salt is different than the density of other brands of salt. Here are some approximations for converting recipes by Thomas Keller.
Diamond Kosher Salt, 1 tablespoon = 12 grams
Morton Kosher Salt, 1 tablespoon = 16 grams, 75%, 3/4
Baleine Sea Salt, 1 tablespoon = 18 grams, 66.7%, 2/3
Table Salt, 1 tablespoon = 20 grams, 60%, 3/5
According to these values, a person using a recipe from ad hoc at home should use 3/4 an amount of Morton Kosher Salt, or a little more than 1/2 an amount of sea salt or table salt. 3/4 tablespoon is equal to 2 1/4 teaspoons. My notes on salt are in my blog post Various Tips (Wisdom) For The Kitchen.