What is SPF & How often should it be applied?

Discover what SPF is, how sun filters protects your skin and learn the best practices for how often to apply sunscreen for effective sun protection.

What's in this article:

Read Time: 5 minutes

What is SPF?
SPF Levels: What is the Difference?
How to Apply SPF Correctly
How Often Should You Reapply Sunscreen?
Facts Overview
Sun Protection for Face and Body
Choosing the Right SPF for Your Skin
Summary
FAQs

Sun protection is essential for helping to maintain healthy-looking skin and preventing long-term damage. Prolonged exposure to the sun can cause sunburn, premature ageing, and increase the risk of skin damage. Sunscreen plays a crucial role in shielding the skin from harmful UV radiation, and SPF is a key factor in choosing the right protection.

What is SPF?

What does SPF stand for?

The SPF on sunscreen stands for sun protection factor, a relative measurement for the amount of time the sunscreen will protect the skin from ultraviolet (UV) rays. The higher the SPF number, the higher the percentage of UVB rays it will block.

How does SPF work?

SPF is determined by measuring the time it takes for redness (erythema) to appear on unprotected skin exposed to a specific dose of UV rays, compared with unprotected skin. So, in theory, an SPF 30 sun cream would last 30 times longer than the same exposure without protection.

In practice, however, it's a different story, as the duration of a sun cream's effectiveness can depend on a number of factors, such as the quantity applied, the UV index, and whether the skin is sweating or swimming. The SPF value should therefore be seen more as a guide, and reapplied regularly.

SPF Levels

The difference between SPF levels

The difference between SPF levels lies in the amount of UVB protection they offer.

SPF15 blocks approximately 93% UVB rays
SPF 30 blocks about 97% of UVB rays
SPF 50 blocks approximately 98% of UVB rays

SPF is determined by measuring the time it takes for redness (erythema) to appear on unprotected skin exposed to a specific dose of UV rays, compared with unprotected skin. So, in theory, an SPF 30 sun cream would last 30 times longer than the same exposure without protection. In practice, however, it's a different story, as the duration of a sun cream's effectiveness can depend on a number of factors, such as the quantity applied, the UV index, and whether the skin is sweating or swimming. The SPF value should therefore be seen more as a guide, and reapplied regularly.

How to apply SPF correctly

Applying sunscreen correctly is essential to ensure maximum UV protection. Even the most effective sunscreen won’t work if it isn’t applied properly.

1. Apply generously

Sunscreen should be applied generously to all uncovered areas. The amount of SPF needed varies by age:

Under 3 years: Avoid exposing babies and young children to the sun at all costs by keeping them in the shade and using protective clothing, a hat, sunglasses and a parasol, as their skin is extremely delicate and more vulnerable to UV damage. For uncovered areas subject to indirect exposure, use a minimum of 5 to 10 ml for babies aged 6 months and over.
Children (3-5 years): At least 10-15ml. For more information on choosing the right sun protection for children, check NIVEA’s sunscreen guide for children.
Children (5-10 years): Require at least 15-20ml for full coverage.
Adults and children over 10: Need at least 30-40ml for the whole body.

Sunscreens For Kids

2. Apply 15-30 minutes before sun exposure

This allows the sunscreen to fully absorb and begin protecting your skin.

3. Cover all exposed areas

Don’t forget areas like ears, neck, scalp (if exposed), back of hands and feet.

4. Use a dedicated face sunscreen

When applying SPF to face, make sure to use a sunscreen formulated for the face and sensitive skin.

How Long Does SPF50 Last & How often should you reapply sunscreen?

The effectiveness of a sunscreen decreases over time, especially with exposure to water, sweat, or towel-drying. Additionally, the lower the SPF and the longer the time since application, the fewer UVB rays will be filtered.

Regardless of the SPF level used, to maintain optimal protection, sunscreen should be reapplied every two hours. If you are swimming, sweating, or towel-drying, it will wear off more quickly, requiring more frequent reapplication. Always check the sunscreen's water-resistant label for specific guidance on reapplication during water activities. Regular reapplication ensures continuous protection throughout the day.

What is SPF & How often should it be applied

Facts Overview

Application: Sunscreen should be reapplied every two hours or more frequently if swimming or sweating.

What is SPF: SPF stands for Sun Protection Factor, indicating the level of protection sunscreen provides against UVB rays.

SPF levels:

SPF15 blocks approximately 93% UVB rays
SPF 30 blocks approximately 97% of UVB rays.
SPF 50 blocks approximately 98% of UVB rays.

Protection with SPF for Face and Body

Protection with SPF for Face

Your face is highly exposed to UV rays, making daily SPF application essential to prevent sun damage and premature ageing. SPF 50 provides higher protection, though lower SPFs work during less intense exposure if applied and reapplied correctly.

Apply sunscreen as the last step of your skincare routine and before you apply any makeup, covering your face, neck, and upper torso. Using moisturisers with SPF offer a convenient way to add SPF into your routine..

Although many makeup products now contain SPF, they are generally not applied in sufficient quantities to offer adequate protection. It's therefore important to ensure you're still using a sufficient amount of sunscreen for optimal protection.

For added convenience, the NIVEA 2in1 Prime UV Serum offers instant SPF 50+ protection and smoothness in a lightweight, fragrance-free formula. Infused with Hyaluron for hydration of the upper layers of the skin and Licochalcone A to boost skin’s natural defence mechanisms (in vitro tested), this serum helps combat premature ageing caused by the sun while keeping skin healthy-looking.. Absorbing quickly without greasiness, it provides seamless daily sun protection.

Designed for convenience, its premium dispenser ensures effortless application. The 2-in-1 action protects and smooths, making it perfect for busy lifestyles. It works well alone or as a primer under makeup, delivering long-lasting hydration and defence for a healthy-looking, and soft.

Face Sunscreens

Protection with SPF for the Body

Applying high SPF properly ensures full-body UV protection, helping to preventsunburn and long-term skin damage. Adults need 30-40ml of sunscreen for complete coverage, while children require 10-30ml depending on age. Apply 15-30 minutes before sun exposure, covering ears, neck, hands, feet, and other exposed areas. Reapply every two hours, especially when exercising, to maintain effective protection.

NIVEA Sun Care Product

Choosing the right SPF for your skin

When selecting sunscreen, it is important to choose an SPF level that suits your skin type, the environment, and the activity you're engaging in.

Fairer skin tones:
For fair skin tones, an SPF 50+ is recommended, as fair skin has lower melanin levels and is more prone to burning and skin damage.
Darker skin tones:
For darker skin tones, an SPF 30+ is usually sufficient, as melanin offers some natural UV defence. However, this does not eliminate the risk of sunburn, hyperpigmentation, or skin damage, so daily SPF application remains essential. In some cases, an SPF 50 may be recommended, particularly to protect the face in the event of high exposure or hyperpigmentation.
Oily skin:
For oily skin, it is recommended to use a lightweight, mattifying sunscreen that will not clog pores or feel greasy. Sun protection products in fluid or gel form generally give a less oily effect than creams. Look for products with an ultra-light texture and ingredients such as Niacinamide to absorb the serum and help prevent imperfections.
Sensitive skin:
For sensitive skin, choose sun creams specially formulated for this skin type and which have been dermatologically tested. Fragrance-free, ethyl alcohol-free, and for sensitive skin options help minimise the risk of redness appearance and discomfort.
Dry skin:
Dry skin benefits from hydrating sunscreens enriched with ingredients like Hyaluronic Acid, Glycerine, or Ceramides to lock in moisture while providing UV protection. Many SPF-infused moisturisers offer both sun protection and hydration, preventing dryness and flaking caused by prolonged sun.

NIVEA Sun Protect & Moisture SPF 50 Lotion

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

The choice between SPF 30 or 50 will depend mainly on your skin type, the UV index and how long you plan to stay in the sun. Although in theory, SPF 50 blocks approximately 98% of UVB rays, as opposed to approximately 97% for SPF 30, the actual protection will depend on the quantity applied, the exposure time and the frequency of application.

Protection levels above SPF 50 only offer marginally additional coverage, and no level of SPF protection can provide 100% protection. In most situations, SPF 30 is adequate protection if applied correctly and regularly; however, SPF 50 remains the safer option for fair skin or heavy exposure. For those seeking trusted sun protection, try our NIVEA Sun Protect & Moisture SPF 50 Lotion.

Summary

SPF measures how effectively sunscreen protects your skin from UVB rays. The higher the SPF, the more protection it offers, but reapplication every two hours is crucial for maintaining sun safety. Apply sunscreen generously and evenly, and make sure to reapply after swimming or sweating for consistent protection.

Frequently Asked Questions

How much sunscreen should I use?

You should apply about 35 ml or the equivalent of 7 teaspoons on all parts of the body, and make sure to reapply it every two hours.

Does SPF 100 offer double the protection of SPF 50?

No, SPF 100 only offers slightly more protection than SPF 50. SPF 50 blocks about 98% of UVB rays, while SPF 100 blocks around 99%. The most important thing is to apply a sufficient quantity and reapply regularly to maintain the level of protection.

Can I rely on sunscreen alone for protection?

While sunscreen is essential, it should be used alongside other protective measures like wearing hats, sunglasses, protective clothing and seeking shade, especially during peak sun hours.

How often should I reapply sunscreen?

You should reapply sunscreen every two hours, and more often if you are swimming, sweating, or towel drying.

Is sunscreen safe for sensitive skin?

Yes, many sunscreens are formulated for sensitive skin. Look for products labelled as “for sensitive skin” or “dermatologist tested.” Ask for advice to your pharmacist if you have doubts.

What is the best SPF?

The best SPF notably depends on your skin type and activity level. SPF 30 to 50 is suitable for most daily activities, while SPF 50+ is recommended for fair skin and in case of extended outdoor exposure (don't forget to reapply regularly).
For aquatic activities, choose a water-resistant SPF 50+ and reapply after swimming or toweling off.

Difference between SPF 30 and 50?

SPF 30 blocks approximately 97% of UVB rays, while SPF 50 blocks approximately 98%. However, these percentages are only indicative and may decrease significantly if insufficiently applied or depending on the activity.
SPF 50 offers a slight increase in protection, especially for those with fair skin or when the UV index is higher.