How Do You Make Unsalted Butter Into Salted Butter?

How Do You Make Unsalted Butter Into Salted Butter? Regular butter contains some salt, and most recipes take this into account. But if you only have unsalted butter when the recipe calls for regular butter, you can add a 1⁄4 teaspoon of salt for every stick or 1⁄2 cup of Challenge Unsalted Butter required. How