Put the science in your hands
The simple version: play with these models to see how the sun reaches your skin and how protection helps.
Educational models that turn the research into something you can explore. Each is illustrative — not a clinical measurement.
UV in your skin
Watch how different UV wavelengths travel through a cross-section of skin.
UVA penetrates deep (photoaging); UVB is absorbed in the epidermis (sunburn + DNA damage).
Educational model — illustrative, not a clinical measurement
Sunscreen calculator
How SPF and how thickly you apply it change real-world protection.
Recommended is 2 mg/cm² — most people apply far less.
SPF 15 ≈ 93% · SPF 30 ≈ 97% · SPF 50 ≈ 98%. But protection scales with thickness: under-applying SPF 30 to half its recommended amount collapses it to an effective SPF of roughly 5.
Educational model — illustrative, not a clinical measurement
Stack your protection
Combining behaviors multiplies their effect. Toggle each on to see the UV dose drop.
Sunscreen alone leaves 15% of the dose, while the full combination leaves only 1.0%. This is why guidelines stress that sunscreen alone is not enough — shade and clothing do the heaviest lifting.
Educational model — illustrative, not a clinical measurement