Estimate tanning time by UV and skin type.
Pigmentation develops from repeated sub-erythemal exposure — doses below the threshold that produces redness. Sixty per cent of your burn time is the conventional working figure for that, so the session length here is deliberately shorter than the burn threshold shown beside it. Building colour is a matter of session count rather than session length, and exceeding the threshold produces damage without accelerating pigmentation.
Sub-erythemal session length
Burn threshold = (200 x skin type factor / (UV x 10)) x sqrt(SPF); session length = 60% of the burn threshold; cumulative = session x sessions planned
There is no medically safe level of UV tanning. This tool describes how pigmentation develops and how to avoid burning; it is not an endorsement of deliberate UV exposure. Consult a dermatologist about your own risk.
Keep each session to roughly 60% of your burn time and repeat over several days. Longer single sessions burn rather than tan faster.
No. Tanning is the skin's response to DNA damage, so any tan represents injury — though avoiding burning substantially reduces the acute harm.
No. Sunbeds deliver high UVA doses and are classified as carcinogenic to humans, with elevated melanoma risk especially for use before age 35.