This came from O magazine's website, quoting Dr B....I hope it is a mistake, I can barely get a 1/4 tsp of ss on my face ! I hope they meant a half a teaspoon for the face and neck...

"Don't Rely on the SPF in Your Foundation"
"To measure SPF in a lab, the chemist puts 2 milligrams of the product on every square centimeter of skin," says Leslie Baumann, MD, professor of dermatology at the University of Miami. That's the equivalent of about half a teaspoon spread over your face! You probably don't wear that much foundation (if you do, please stop that too). Instead, apply a broad-spectrum SPF 30 sunscreen, wait a few minutes for it to soak in, and then follow with foundation. "

— Kate Sandoval