What is SPF? How long does 30/50 last & which do you need?

SPF is essential to protect your skin from UV rays in your daily life. Discover how SPF works, how long it lasts, what factor numbers mean, which to use & how to apply.

What’s in this article?

What does SPF stand for?
What does the SPF number mean?
How does SPF work?
What SPF should you choose?
How to apply SPF
How long does SPF50 last & how often should you reapply?
Which SPF for the face?
Coppertone SPF

What does SPF stand for?

SPF stands for Sun Protection Factor and is a measure of how well a sunscreen protects your skin from UVB rays and sunburn. The higher the SPF, the longer the protection will last. While higher SPFs block more of the sun’s UVB rays, no sunscreen can block 100% of the sun’s UVB rays.

Learn everything you need to know about SPF including how long factor 50 lasts, how it works, and which number is best suited to your skin.

What does the SPF number mean?

The SPF number tells you how long it might take you to get a sunburn after applying it, versus not wearing any at all. As an example: if you can spend 10 minutes in the sunlight without burning, a lotion with SPF30 will multiply this "self-protection time" by 30 to equal 300 minutes.

But keep in mind that this is just an approximation since you might not be taking as long to burn depending on the season, the weather, your skin type or even your geographic location.

How does SPF work?

The ingredients in sunscreens work to protect skin by either reflecting, absorbing or scattering UV rays, reducing the risk of sun induced damage. Mineral (AKA physical) sunscreens work to reflect UV light, whereas chemical sunscreens absorb it. The amount of UV rays filtered depends on the level of SPF you apply:

SPF15 stops up to 93% UVB rays
SPF30 stops up to 97% UVB rays
SPF50 stops up to 98% UVB rays
SPF100 stops up to 99% UVB rays

UVB rays can never be totally filtered, which is why it is important to reapply SPF protection at least every 2 hours.

What SPF should you use?

The AAD (American Academy of Dermatology) recommends using a sunscreen with an SPF of at least 30.

Choosing the right SPF for your skin type

Opposite to what we may think, the percentage of melanin present in your skin, which makes your skin color darker, does not influence the level of SPF you need. Darker skin still needs to be protected against harmful rays. However, when you have a lighter skin tone, you should apply sunscreen more frequently, as you have less melanin in your skin and less natural protection from the sun.

What you should remember about the SPF number is: the higher it is, the more UVB rays are blocked, protecting your skin from the sun. If you have a skin condition and are unsure about the SPF you should be wearing, consult with your doctor for advice.

Choosing the right SPF for babies and kids

The skin of little ones is especially delicate so always opt for a minimum of SPF50 to maximize their protection. The Coppertone range of kids and baby sunscreens all offer SPF50 or above to ensure their skin is as protected as possible from UV rays.

Coppertone kids and baby sunscreens come in a variety of application formats so you can apply them with ease, with varying formulas from water resistant (up to 80 minutes) to hypoallergenic with nourishing ingredients like Vitamin E and soothing Aloe Vera.

Coppertone Kids & Babies

Should you choose SPF 50 or 30? What’s the difference?

SPF 50 stops up to 98% of UVB rays, as opposed to up to 96.7% provided by SPF 30. Protection levels above SPF 50 provide marginal additional coverage and no level of SPF can stop 100% of UVB rays. The SPF number indicates how long it might take you to get a sunburn after applying it, versus not wearing any at all. Following the example above: if you can spend 10 minutes in the sunlight without burning, a lotion with SPF30 will multiply this "self-protection time" by 30 to equal 300 minutes, and a lotion with SPF50 will equal 500 minutes. That said, this is only an estimate as each person’s skin takes a different amount of time to burn, and other factors can be at play such as the weather, skin type, and geographic location.

How to apply SPF

You should make sure to apply SPF 15 minutes before sun exposure to all areas of your body. Improper application of sunscreen will leave parts of your skin exposed to the sun's dangerous UV rays. When applying SPF appropriately, you should completely cover any uncovered areas and reapply regularly as required to maintain a safe amount of UV protection.

Remember to always follow packaging directions for how to best apply your SPF product.

Remember it is possible to burn through clothing – particularly lightweight or thin tee shirts, so you should consider applying SPF underneath on days when the sun is particularly strong.

The recommended amount of SPF to apply for full body coverage for an adult is at least 1 ounce.

To apply SPF on your face properly, apply it as the very last step of your skincare routine, and cover your chest area and neck. Apply sunscreen 15 minutes before sun exposure so it is protected from the sun’s damaging rays.

woman smiling with Coppertone sunscreen on her face

How long does SPF 50 last & often should you reapply?

SPF50 will allow you to stay in the sun 50 times longer than you could if you did not have any sunscreen on. The longer the length of time since application, the less UVB rays will be filtered, so aim to reapply at least every 2 hours; however, always follow the instructions on the product’s packaging.

You should reapply SPF more frequently if swimming or doing sports - as sweat and water can lower protection faster. Using a sport-specific sunscreen such as the Coppertone SPF 50 Clear Lotion that resists sweat and is and water-resistant (80 minutes) is recommended to help stay sun safe during activities. Keeping travel sunscreen of SPF 30 or 50 can also be a handy way of ensuring your protection is topped up throughout the day.

Sport Sunscreens

Which SPF for the face?

Experts say to look for facial sunscreens that are SPF 30 or higher and provide broad-spectrum coverage.

Sun induced damage is one of the main causes of premature ageing, protecting your skin from its rays can help maintain a youthful-looking complexion. Although aging is a beautiful process, sun damage should be avoided.

Your face is one of the most exposed parts of your body, therefore applying SPF daily is highly recommended to keep it protected. Getting into the habit of applying a specific face sunscreen at the end of your morning skincare routine is one of the best ways to do this.

Try using the Coppertone Every Tone Invisible Finish Face SPF 55 after applying your daily moisturizer to give your skin the protection it needs. The lightweight and invisible formula makes it ideal as a base underneath makeup.

Remember to keep your sunscreen on hand throughout the day so you can reapply protection as needed.

Face Sunscreens

Coppertone SPF

Coppertone has been providing continuous innovation for more than 75 years and is voted the most trusted sunscreen brand in the US*. The full range of Coppertone Sunscreens have been developed and tested by experts for reliably effective protection, whilst containing additional nourishing ingredients that care for your skin.

Whether you require durable SPF for sport, mineral SPF for sensitive skin, SPF for babies and kids, moisturizing protection for the whole family or something for an extra shimmer and glow – Coppertone's range has you covered.

Browse the range of Coppertone sunscreens to find those suited for your needs.

Coppertone Sunscreens