SPF 30 vs SPF 50: The difference is smaller than you think

SPF 30 blocks about 97% of UVB rays, SPF 50 blocks about 98% — just a 1% gap. That extra bit matters if you burn easily or stay in direct sun for hours, but for most people SPF 30 is enough if you reapply. The real problem is that nobody applies enough sunscreen (you need a shot glass full for your body), so the practical difference shrinks even more. Wear whichever one you’ll actually apply and reapply.