Tan Session Time Estimator
If you’re going to be out in the sun, the least harmful path is to stay well under your burn threshold. This estimates a cautious session limit from the UV index, your skin type, and any SPF — and is honest about which skin types shouldn’t chase a tan at all.
Suggested session limit
No tan is truly “safe” — a tan is the skin’s response to UV damage. This only helps you avoid the far worse harm of burning.
Colour without the burn
Any dermatologist will tell you a tan is damage. But people spend time in the sun for all sorts of good reasons, and if you’re going to, the meaningful line to hold is the burn line. Reddening skin has crossed from “stressed” into “injured,” and repeated burns are the exposure most strongly linked to melanoma. Staying under a comfortable fraction of your burn time keeps you on the safer side of that line.
The estimate can only be rough — your real threshold is personal — so build in a margin, keep sessions short, seek shade at midday, and reapply sunscreen. And if your skin type simply burns, take that at face value: there’s no version of this that ends well for Type I or II skin.
Frequently Asked Questions
Is there such a thing as a safe tan?
Not really. A tan is the skin producing extra melanin in response to UV damage — it's a sign of harm, not health, and it comes with the same long-term risks of ageing and skin cancer. The honest goal isn't a 'safe tan' but avoiding the much greater, immediate harm of a burn if you're going to be in the sun anyway.
How does the estimate work?
It takes the time it would take your skin to reach a just-perceptible burn at the current UV index and SPF, then suggests staying under a fraction of that — 50 to 60% by default — to leave a margin. Lower the percentage for more caution.
Why does it tell some skin types not to tan?
Fitzpatrick skin types I and II don't tan in any meaningful way — they burn, freckle, and peel. For those skin types there is no session length that produces a gradual tan safely, so the tool says so plainly rather than suggesting a number.
What about tanning beds?
Indoor tanning beds emit concentrated UV and are classified as carcinogenic to humans by the World Health Organization. This tool is about outdoor sun only and is not an endorsement of sunbeds, which major health bodies recommend avoiding entirely.
General guidance only, not medical or dermatological advice. No tan is risk-free; when in doubt, cover up and see a professional about your own skin.