How do I convert measurement of all-purpose flour to cake flour?

Lazy

I just found this on www.practicalpantry.com, and believe it's the same thing that's on the back inside cover of the betty crocker cookbook:

For 1 cup of cake flour, substitute 1 cup minus 2 tablespoons all-purpose flour. You also can try substituting 3/4 cup all-purpose flour plus 2 tablespoons cornstarch for every 1 cup of cake flour called for in a recipe. To substitute cake flour for all-purpose flour, use 1 cup plus 2 tablespoons cake flour for every 1 cup all-purpose flour called for in a recipe.
If a recipe for a delicate cake, such as angel food or sponge cake, calls for cake flour, do not try substituting all-purpose flour. Such a substitution could cause the delicate cake to collapse.

Thanks, czyadgrl!