11 Sun Protection & SPF Facts About India You Should Know

7. How much to apply and how often to reapply for real protection

Getting protection from SPF numbers depends on applying the right amount and reapplying on schedule. The U.S. FDA recommends reapplying sunscreen every two hours, or immediately after swimming or heavy sweating (FDA guidance). For body coverage, a good visual measure is about one ounce—the size of a shot glass—for full-body application. For the face, two fingertip units (roughly two strips from the tip to the first crease of the index finger) cover the face and neck. Apply sunscreen about 15 minutes before stepping into strong sun if you’re using a chemical formula; mineral sunscreens protect on contact. During long outdoor events—like helping a street vendor or commuting under an open sky—remember to reapply even if your SPF label says “long-lasting.” No sunscreen stays perfectly effective through heavy sweating, water exposure, or simply wearing off over several hours.