A shot glass worth.

Yes, roughly one ounce (30ml) — a full shot glass — for your whole body. That’s about a palmful of lotion or a generous teaspoon per limb.

Most people use less than half that. Thinner application means lower SPF than the label says. Your SPF 50 becomes SPF 20 real quick. Sunburn is not a moral failing, but it is preventable with enough goop.

Apply it indoors before getting dressed, let it dry for 15 minutes, and reapply every two hours or after swimming. Your future skin will thank you.