How much salt is in each stick of salted butter compared to unsalted?

Question

I am using a recipe of my mom's that uses salted butter. All I have is unsalted. How much salt should I add per stick?

It is for a toffee:
2 stick butter
1 cup sugar
1/2 cup fine chopped nuts
1/3 cup chocolate chips

Heat first three until looks like brown paper bag spread over cookie sheet and top with chocolate chips. Smooth chocolate over top and chill.

It might be a bit hard to do it to taste because it is very hot at that point. Thank you though.

Answer 1

"The amount of salt in a stick of butter can vary, which can cause problems in your cooking. Salted butter can contain as much as 3 percent salt, or about 3/4-teaspoon per stick"

Answer 2

You should salt to taste.....unsalted butter is fresher and in my opinion better.....if you look at recipes from top chefs around the world they will use unsalted butter 99% of the time.