SPF 30 vs SPF 50: what is the difference?

SPF 50 provides more protection against sunburn than SPF 30 under test conditions. For your face, 50 is a sensible choice if you burn easily, spend a long time outdoors or simply prefer a higher factor. SPF 30 also offers good protection when you apply enough and reapply on time. With either, choose protection against both UVA and UVB.

How much difference does it make?

The familiar percentages help explain the comparison. They are a simplified way of describing UVB protection with correct application, rather than a measurement of what reaches your skin at every moment.

The middle column differs by roughly 1.3 percentage points. Looking at what passes through, however, the amount falls from about 3.3 to 2 parts in a hundred. In this simplified calculation, SPF 50 lets through about 40% less than SPF 30. That is why a small change in the filtered percentage still means extra protection. It does not mean a 40% reduction in skin cancer risk. Cancer Council explains the SPF percentages.

This comparison assumes careful application. A conventional SPF test on skin uses 2 mg per cm². Spreading a little leftover SPF 50 from your hands across your face will not automatically give you the protection on the label. Our guide to what SPF and SPF 50 mean explains the test.

When should you choose 30 or 50?

An ordinary day outdoors

For a walk to the shops or lunch outside, SPF 30 with UVA protection is a useful starting point. The AAD recommends at least SPF 30. Apply it carefully even for shorter outings and check the local UV index. If you would rather keep one product in your routine, you can simply choose SPF 50; you do not need separate bottles for different kinds of day.

Do not judge the sun by the temperature alone. UV levels can be high on a cool day. Have lunch under a tree or a covered area, for example, and cover your skin where practical. Our guide to facial sunscreen explains how sunscreen, clothing and shade work together.

Longer outings or skin that burns easily

For a long walk, outdoor exercise or skin that burns easily, SPF 50 or 50+ is a sensible choice. Use the higher factor for greater protection, rather than to extend your time in the sun. Put the bottle in an easy-to-reach pocket and plan a break to reapply before carrying on.

If you will be swimming or sweating heavily, also check for water resistance. That is a separate label claim; the number 50 tells you nothing about it. Read our practical guide to sunscreen for sport and water resistance.

A formula you are happy to use generously

Compare how products feel when you apply the recommended amount. A cream you keep wiping off because it feels too greasy is less suited to your routine. Choose an SPF of at least 30 that you can spread generously; look for a more comfortable SPF 50 if you want to keep the higher protection. A higher factor does not automatically mean a thicker or greasier cream.

If you wear makeup, let your sunscreen settle as directed before continuing. Try the combination on an ordinary morning, using the full amount of sunscreen you need. Makeup with SPF does not replace that generous base layer.

Three things that matter with either factor

1. Check UVA protection. On a European label, look for the UVA indication, often UVA inside a circle. SPF mainly describes protection against sunburn. The European recommendation also sets a minimum level of UVA protection.
2. Apply generously and evenly. Include your hairline, the sides of your nose, ears and neck. Work around each area so that you do not miss the edges. Our guide to amounts for the face, neck and ears can help.
3. Reapply outdoors. Do so about every two hours and after swimming, heavy sweating or towelling, following the label. Even SPF 50 does not stay in place all day by itself. This follows dermatologists' advice on sunscreen use.

Three more common questions

Does SPF 30 under SPF 50 add up to SPF 80?

No. You cannot add the factors together. Do not mix products to create an intermediate factor either. Apply enough of one suitable sunscreen; extra skincare does not turn the tested factors into a sum.

Is SPF 50 gentler on sensitive skin?

The factor tells you the measured protection against sunburn, not how your skin will react to the ingredients. Choose a formula you tolerate. If you have a known allergy or skin condition, use your clinician's advice to guide ingredient choices.

Is SPF 50+ the same as SPF 50?

On a European label, no: 50+ belongs to a higher test category. The plus sign does not change when you need to reapply. The SPF guide linked above explains the exact threshold.

Using sunscreen properly helps prevent skin cancer and protects against sunburn and premature skin ageing. Soluveli is still in development; we are working on facial sunscreen that fits comfortably into a daily routine. Visit the Soluveli homepage to read about its development and sign up for one email when we launch.