At 4 sticks to a pound of butter, you would need 0.525 cups of a popular spreadable product to equal 1 stick. This was found by weighing a well packed 1/4 cup of the spread on a digital scale. I got 54.3 grams. 0.525 cups is 1/2 cup plus about a teaspoon. You would probably be safe to just use a half cup.