About SunStoke
Most sun advice comes down to two words — “wear sunscreen” — and then leaves out everything that actually matters: how much to use, how often to put it back on, how long your own skin can be out before it burns, and when the sun is doing you good rather than harm. SunStoke exists to fill in those specifics with small, honest tools and plain-language guides, so you can enjoy the sun without quietly paying for it later.
Rather than long articles you have to read end to end, the site is built around a handful of single-purpose calculators, each aimed at one decision. The SPF Reapplication Timer tells you when your sunscreen has likely worn off, because water, sweat, and towels strip it away long before the day ends. The UV Index Safe-Exposure Calculatorestimates how long unprotected skin of your type can take today’s UV before it burns. The Sunscreen Amount Calculator turns the dermatologist’s 2 mg/cm² rule into grams and teaspoons for the parts of you that are exposed. The Tan Session Time Estimatorgives a cautious time limit for building colour gradually — and an honest note that some skin only burns. The Vitamin D Sun-Exposure Estimator gauges the brief midday exposure that may support vitamin-D synthesis, well short of a burn. And the Sunburn Risk Score pulls the UV index, your skin type, time outside, SPF, altitude, and reflective surfaces into a single Low-to-Extreme read.
Beyond the calculators, the blog and learnsection cover how SPF really works, chemical versus mineral filters, how much to apply, reading the UV index, the myths around “safe” tanning, protecting different skin types, and sunburn first aid; and the Sun & Skin Museum is a browsable collection on the sun itself, the biology of human skin, the history of sunscreen and cosmetics, and ultraviolet light, with every entry, image, and fact drawn from Wikipedia and Wikimedia Commons.
A few things worth stating plainly. SunStoke is an independent site, not a clinic, and not affiliated with any sunscreen brand or manufacturer. It is supported by advertising, which is how the tools stay free with no account required. Everything here — every exposure time, amount, risk score, and article — is general educational information built on published conventions and the numbers you enter, not personalised medical or dermatological advice. Skin, medication, and UV conditions vary enormously from person to person and day to day, so for anything concerning a mole, a burn, a reaction, or a skin condition, see a doctor or a dermatologist. If a tool looks off, or there’s a calculator you wish existed, the contact page is the place to say so.