This Sunbathing Calculator Lets You Know When You've Had Enough Rays

Sun protection is so important.

During summer — when we are enjoying outdoor activities the most — it's especially vital to protect ourselves from the sun. This is so important given that the Centers for Disease Control and Prevention reported that skin cancer is the most common cancer in the United States, and those who have a history of sunburns, especially in earlier life, can increase their risk of skin cancer.

We know the importance of wearing sunscreen to stay protected, but we sometimes don't apply — and reapply — it correctly. Many of us are also unaware of how much the weather and location can impact our sun safety.


To help people stay safe and protected in the sun, Dr. Małgorzata Koperska created a tool called the Sunbathing Calculator.

The Sunbathing Calculator, from Omni Calculator, is easy to use and gives users clear results. 

"Do you always remember to put on sunscreen before going outside? Are you sure that you use enough? The Sunbathing Calculator will tell you when's the time to go back under an umbrella not to suffer from a sunburn," it says on the website.

Users can select a basic or advanced mode on the Sunbathing Calculator. The basic mode allows users to indicate the sunlight intensity, altitude, whether there is water or snow, their skin type, and the SPF in their sunscreen. The page also lists tips and guidelines if users aren't sure what their skin type is.

After the data is plugged in, the tool will calculate approximately how much time you can safely spend in the sun.

The advanced mode features the same categories, but also lets users enter in the UV index of their location.

"The equation I used to calculate the maximum safe time spent in the sun sounds a bit complicated," Dr. Koperska explained to Bustle. "It's the skin phototype coefficient times the cream's SPF, divided by the current UV index, altitude coefficient, and reflecting ground coefficient."

Even if the average user doesn't fully understand the formula, they can understand the guidelines and tips the Sunbathing Calculator features.

The important thing is that people still follow sun safety tips and realize the Sunbathing Calculator is just a guideline, and is not to be used as an invitation to stay out in the sun.

Dermatologist Dr. Michael Swann points out that the calculator doesn't factor in the type of sunscreen, reapplication, and the amount of activity and sweat involved. "You could use SPF 100 and reapply every two hours but still be getting incredibly high levels of UVA [ultraviolet A] exposure, which contributes to melanoma, the most deadly form of skin cancer, as well as many cosmetic issues (uneven pigmentation, loss of elasticity and wrinkles)," he explains. "That's because the SPF number is really a measure of protection against sunburns (measured by redness) caused by UVB [ultraviolet B], but doesn't necessarily qualify the damage caused by UVA."

"Currently, if UVA frequencies are minimized by the sunscreen, the label will say 'broad spectrum' sunscreen. This is a non-specific way to show that at least a portion of UVA is protected by the sunscreen." He adds that chemical UVA blockers are known to be degraded by the sun, and must be reapplied routinely to be effective. Physical sunscreens work by reflecting UVA and UVB and are preferred for overall UV risk.

Dr. Janet Prystowsky expresses concern about how people will use the calculator accurately. "Generally, many people don't apply enough sunscreen (i.e. a thick layer). I like to tell people that their SPF 50 will give them about a SPF 25 amount of protection, and SPF 30 will give them about a SPF 15 amount of protection," she explains. "That way I hope to get people to try to use about twice as much sunscreen as you think you need if you want the SPF to match its rating." 

Without the tip, someone might be entering a SPF amount into the calculator given what it says on their bottle of sunscreen when in reality their protection would be much less because of what they're applying. This could then skew the results.

Something Dr. Prystowsky likes is the fact the calculator shows sun intensity from around the world.

"I like that the calculator gives people an indication that sun intensity will be different at higher altitudes and different locations around the globe."

She continues, "Many people are not aware of how intense the sun can be at the top of a mountain when skiing. A lot of vacationers looking to escape winter in the north east also don't realize the island sun can be far more intense than even a typical summer day in the north east."

She notes that the Sunbathing Calculator helps people gain a further understanding of how cloud coverage can impact skin, but worries about people taking advantage of their "safe" time. She cautions, "I worry about people being overly reliant on the allowable exposure the calculator comes up with. I think the better approach is to recognize the sun is more intense and to make an added effort to make sure you have the right level of protection."

To stay safe in the sun, Dr. Prystowsky recommends using a mineral-based broad spectrum high SPF sunscreen, which are preferable to chemical sunscreens because the long-term effects of chemical sunscreens aren't well understood. 

Remember to follow sun safety tips and consider adding other lifestyle products into your routine to increase your protection

(H/T: Elite Daily)

Cover image via  Andrey Yurlov I Shutterstock


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