UV Burn Time Calculator
Pick a UV index and your Fitzpatrick skin type to see roughly how many minutes unprotected skin takes to start burning — and the SPF guidance for that level. Whether you’re checking before a beach day or wondering what UV index tans without burning, the full UV 1–11+ table below has every combination.
How long until you burn?
~17 minutes to sunburn
UV 8 (Very High) · unprotected type III skin
Wear SPF 30–50+ broad-spectrum sunscreen, reapply every 2 hours, and avoid the sun 10 a.m.–4 p.m.
Approximate first-redness estimate from minimal erythemal dose (MED) reference values for each Fitzpatrick skin type — not medical advice, and not a safe-exposure budget: UV damage accumulates before skin visibly reddens. See methodology.
The EPA UV Index scale
The UV index is an open-ended scale of sunburn-producing ultraviolet radiation at the surface, standardized by the WHO and reported in five EPA bands. Burn times below UV 3 aren’t tabulated because the EPA classes that exposure as minimal risk for most people.
EPA UV Index scale
Burn time table: every UV index, every skin type
Approximate minutes to first visible reddening for unprotected skin, for each UV index 1–11+ and each Fitzpatrick skin type I–VI. Type III is the model’s anchor; other types scale by their minimal erythemal dose (MED).
| UV index | EPA band | Type I | Type II | Type III | Type IV | Type V | Type VI |
|---|---|---|---|---|---|---|---|
| 1 | Low | minimal | minimal | minimal | minimal | minimal | minimal |
| 2 | Low | minimal | minimal | minimal | minimal | minimal | minimal |
| 3 | Moderate | 30 min | 37 min | 44 min | 67 min | 89 min | 148 min |
| 4 | Moderate | 22 min | 28 min | 33 min | 50 min | 67 min | 111 min |
| 5 | Moderate | 18 min | 22 min | 27 min | 40 min | 53 min | 89 min |
| 6 | High | 15 min | 19 min | 22 min | 33 min | 44 min | 74 min |
| 7 | High | 13 min | 16 min | 19 min | 29 min | 38 min | 63 min |
| 8 | Very High | 11 min | 14 min | 17 min | 25 min | 33 min | 56 min |
| 9 | Very High | 10 min | 12 min | 15 min | 22 min | 30 min | 49 min |
| 10 | Very High | 9 min | 11 min | 13 min | 20 min | 27 min | 44 min |
| 11+ | Extreme | 8 min | 10 min | 12 min | 18 min | 24 min | 40 min |
“Minimal” = the EPA Low band (UV 1–2), where sunburn risk is minimal for most people and no minutes figure is meaningful. Skin types, most to least sun-sensitive: I (very fair — always burns, never tans); II (fair — burns easily, tans minimally); III (fair to medium — sometimes burns, tans gradually); IV (olive — burns minimally, tans easily); V (brown — rarely burns, tans darkly); VI (deeply pigmented — very rarely burns).
UV Index 8 Burn Time
UV 8 is the low end of the EPA Very High band. Unprotected, the most sun-sensitive skin (Fitzpatrick type I) can start to redden in about 11 minutes, fair-to-medium type III in about 17 minutes, and deeply pigmented type VI in about 56 minutes — an MED-model estimate, not medical advice. The UV 8 row of the burn-time table lists every skin type.
How Long Can I Tan at UV 7?
UV 7 is the top of the High band, and there is no burn-free tan at it — a tan is the skin’s injury response to UV. What UV 7 sets is a burn clock: unprotected type I skin can start to redden in roughly 13 minutes, and fair-to-medium type III in about 19 minutes. Dermatology groups recommend shade, cover, and SPF over any target tan-time, and sunless tanning products over intentional UV exposure. The burn-time table lists the UV 7 times for all six skin types.
How the burn-time model works
Every number on this page comes from one standard dosimetry approximation: time to first redness ≈ your skin type’s minimal erythemal dose (MED) divided by the erythemal irradiance the UV index represents. The anchor is Fitzpatrick type III (fair-to-medium skin); the other five phototypes scale that baseline by the standard MED reference set for the six types (Fitzpatrick, 1988) — type I burns in roughly two-thirds the time of type III, and type VI takes roughly 3× longer. It is the same formula behind the burn-time verdict on every Weather Story city UV page.
Honesty notes: these are first-redness estimates for midday sun on unprotected skin — not a safe-exposure budget (UV damage accumulates before skin visibly reddens), and not medical advice. Altitude, reflection off water, sand, or snow, and some medications shorten every number in the table.
UV Index Today
The burn times on this page are fixed reference figures. The actual UV index where you are changes every day with the sun’s angle, the season, your latitude and altitude, and cloud cover — peaking for a few hours around solar noon. To see today’s UV index and peak-burn window for your city, use the live UV index by city tool.
Frequently asked
- How long does it take to get sunburned at UV 7?
- At UV 7 (High), unprotected very fair type I skin can begin to redden in roughly 13 minutes, and fair-to-medium type III skin in about 19 minutes — an MED-model estimate, not medical advice.
- What UV index is good for tanning?
- No UV level tans without damage — a tan is the skin's injury response to UV. Below UV 3 burn risk is minimal for most people, but dermatology groups recommend sunless tanning products over intentional UV exposure at any index.
- Can you get sunburned at UV 1 or 2?
- At UV 1–2 (the EPA Low band) sunburn risk is minimal for most people and no protection is needed for the average person outdoors, though very sun-sensitive skin, reflective surfaces like snow or water, and long exposure can still add up.
- How much longer can I stay in the sun with SPF 30?
- In principle SPF multiplies your unprotected burn time — SPF 30 blocks about 97% of UVB — but real-world application is thinner than the lab standard, so the practical guidance is to reapply every 2 hours rather than budget 30× the minutes.
- What is the fastest anyone burns at UV 11+?
- At UV 11 (Extreme), the model puts unprotected type I skin at roughly 8 minutes to first redness — and even deeply pigmented type VI skin at about 40 minutes.
- Do darker skin types need sun protection at all?
- Yes. Higher Fitzpatrick types burn more slowly — type VI has roughly 5× the burn threshold of type I — but UV damage, photoaging, and skin-cancer risk still accumulate before any visible redness.
- What does the UV index actually measure?
- The UV index is the WHO's open-ended scale of sunburn-producing UV at the surface: 0–2 Low, 3–5 Moderate, 6–7 High, 8–10 Very High, 11+ Extreme. At UV 3, type III skin burns in about 44 minutes unprotected.
More UV & sun resources
- Today’s UV index by city
- UV Index Scale: What Low, Moderate, High, and Extreme Mean
- How Long Until You Burn? UV Index and Sunburn Time
- Sun, UV, and Vitamin D: How Much You Actually Need
- When Is UV Strongest? Time of Day, Season, and Latitude
- Tanning and the UV Index: Is There a Safe Number?
- UV Index and Skin Cancer Risk: What the Numbers Mean
- How much daylight your city loses by the winter solstice