June 13, 2026, 6:09 am | Read time: 3 minutes
Blue skies, crowded outdoor pools, and well-visited lakes: Germany has already experienced early summer temperatures. But with many hours of sunshine comes the risk of sunburn and long-term skin damage. It’s not just the right SPF that’s crucial, but also the amount of sunscreen applied. Experts warn: Many people use significantly too little sunscreen, which affects its protective effectiveness.
Why Most People Apply Too Little Sunscreen
“We need more sunscreen than most people think,” says dermatologist Prof. Michaela Axt-Gadermann. “Many apply sunscreen too thinly. As a result, the SPF stated on the sunscreen package is often not achieved.” Dermatologist Dr. Timm Golüke also points out that many people frequently underestimate the required amount: “Studies calculate about 2 milligrams per square centimeter of skin.”
Teaspoon Rule and Two-Finger Rule as Guidelines
To ensure sunscreen provides full protection, Axt-Gadermann recommends the so-called teaspoon rule: “Preschool children need 4 teaspoons (20 ml) of sunscreen from head to toe, school children need 5 (25 ml), and adults at least 6 teaspoons (30 ml).”
For specific body areas, the two-finger rule is suitable. Golüke explains: “The face and neck need about two finger lengths of sunscreen, an arm the same, a leg more like three to four.” Those who have difficulty applying larger amounts evenly can first apply a layer, let it absorb briefly, and then reapply.
Reapplying Remains Essential
Especially when swimming or sweating heavily, the protective effect diminishes over time. Therefore, regular reapplication is necessary. “Anyone staying in the sun longer or drying off after swimming must reapply, because waterproof does not mean rub-proof,” says Axt-Gadermann. Proper application is also important. “It’s crucial that sunscreen is not massaged in. If rubbed intensely into the skin, it loses much of its protective effect. A better protection is a uniform film that is spread on the skin but not rubbed in,” explains the physician.
Which SPF Is Right?
Besides the amount, the SPF plays a central role. Axt-Gadermann recommends: “The SPF should be at least two to three times the current UV index—and a UVA protection is also important.” People with fair skin should choose products with SPF 20 to 50+, depending on UV exposure. For darker skin types, an SPF between 15 and 30 is often sufficient.
Stricter rules apply to children. “Babies should not be in direct sunlight at all, and children need a very high SPF (50+),” says Axt-Gadermann. Older people should also protect their skin particularly well, as it becomes thinner with age. Here, an SPF between 30 and 50 is recommended.
Special Care for Sensitive Skin Areas
Certain body regions are particularly exposed to the sun. These include the nose, forehead, ears, shoulders, neck, and décolleté. These so-called “sun terraces” should be carefully covered with sunscreen. “In everyday life, SPF 30 is a good minimum protection, while on vacation, in the mountains, or by the water, SPF 50 is better,” says Golüke.
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Shade Does Not Replace Sunscreen
Even those who mostly stay in the shade are not completely protected from UV radiation. According to experts, the protection under a tree corresponds to an SPF of about 5 to 15. A sun umbrella only achieves an SPF of 5 to 10. Water, sand, or bright house walls additionally reflect UV radiation and can enhance its effect. Therefore, sunscreen should also be considered in the shade.
Protect Eyes and Skin Even in the Car
Not only the skin but also the eyes can be damaged by UV rays. Therefore, experts recommend a high-quality pair of sunglasses with UV filters. They also advise applying sunscreen during car rides and wearing sunglasses if needed to reduce the risk of eye damage, skin damage, and skin cancer.