SPF 30 vs SPF 50: The real-world difference is tiny

SPF 30 filters about 97% of UVB rays, SPF 50 about 98% — that extra 1% barely matters because most people don’t apply enough to get labeled protection anyway. What actually counts is applying generously, reapplying every two hours, and not skipping days. A bottle of SPF 30 you actually use beats SPF 50 you hoard.