SPF 100 vs SPF 50: SPF 50 wins for real-world protection

SPF 50 blocks about 98% of UVB rays, while SPF 100 blocks about 99% — the extra 1% doesn’t meaningfully improve protection in practice. People treat SPF 100 like a force field and skip reapplying, which is dangerous. SPF 100 also tends to be more irritating and expensive. You’re better off with SPF 50 that you reapply every two hours.