Sunscreen SPF Calculator
Find out how long your sunscreen protects you based on SPF value, skin type and the current UV index.
UV Index guide for India
| UV Index | Level | Protection | Indian Context |
|---|---|---|---|
| 1–2 | Low | Minimal — hat optional | Winter mornings, north India Nov–Jan |
| 3–5 | Moderate | SPF 15+, hat | Mumbai winters, hill stations summer |
| 6–7 | High | SPF 30+, shade at noon | Most of India March–October |
| 8–10 | Very High | SPF 50+, avoid 10am–4pm | Beach destinations, plains summer |
| 11+ | Extreme | SPF 50+, stay indoors midday | High altitude, Rajasthan peak summer, Andaman |
Frequently asked questions
Does SPF 50 mean twice the protection of SPF 25?
Not exactly. SPF measures how much UVB radiation is blocked. SPF 15 blocks ~93%, SPF 30 blocks ~97%, SPF 50 blocks ~98%, SPF 100 blocks ~99%. The doubling of SPF does not double protection — higher SPF mainly provides a slightly longer safe duration.
Should I use sunscreen in winter in India?
Yes. UV rays are present year-round and pass through clouds. UV index in Indian cities rarely drops below 4 even in December–January, especially in south India and at altitude. SPF 15–30 is advisable daily.
How much sunscreen should I apply?
Dermatologists recommend about 1/4 teaspoon (1.25 ml) for the face and 1 teaspoon (5 ml) per body area. Most people apply far too little, reducing effective protection significantly. Apply 20–30 minutes before sun exposure.
Is SPF in moisturizer enough?
SPF-containing moisturisers and BB creams are better than nothing, but most people apply far less than the amount needed to achieve the stated SPF protection. Use a dedicated sunscreen for outdoor activities.
What SPF is recommended for a beach holiday?
A minimum of SPF 30–50 with broad-spectrum (UVA + UVB) and water-resistant formulation. Reapply every 80–90 minutes when swimming. UV index at Indian beaches (Goa, Andaman, Kerala) frequently exceeds 8–10 in summer.