One-third cup of butter equals 5 tablespoons plus 1 teaspoon. Since there are 16 tablespoons in 1 cup, dividing by 3 gives approximately 5.33 tablespoons. For practical cooking purposes, you can round this to about 5.5 tablespoons (5 tablespoons + 1 teaspoon), or use a kitchen scale if you need precision—1/3 cup of butter weighs roughly 76 grams or 2.7 ounces. Most bakers and cooks use the 5 tablespoons + 1 teaspoon measurement as a straightforward conversion, though some recipes may simply say "5 tablespoons" as a close approximation. If you're measuring softened butter, this conversion works smoothly; for stick butter, 1/3 cup is just slightly more than one-third of a standard 8-tablespoon stick.