How much sunscreen should be applied at one time?

How much sunscreen should I reapply? How much sunscreen should be applied to achieve sufficient sun protection? The sun is getting stronger and stronger. I bought some sunscreen, but how much should I apply to achieve sun protection? Can applying sunscreen block all ultraviolet rays?

How much sunscreen should you reapply?

Reapply sunscreen with an amount about the size of a dime. When reapplying sunscreen, apply the same amount as when you first applied it, about 2-2.5 grams on the arms and about 1-1.5 grams on the face. When reapplying sunscreen, do not apply too little, otherwise it will not have the desired sun protection effect.

How much sunscreen should I use at one time

The consumption rate of sunscreen products is directly related to their effectiveness. To achieve satisfactory sunscreen effects, the amount must be sufficient and the consumption rate must be fast enough. The dosage standard for testing SPF is 2.0 mg/cm2, which is multiplied by the facial area to get the dosage of sunscreen product. The shape of a human face is approximately elliptical, with an area of ​​approximately 360cm2. This data is actually very rough and can only be used as a reference. Substituting the data into the previous calculation formula, we can get: 2.0mg/cm2×359cm2≈0.72g. That is, the amount of sunscreen product used on the face is about 0.72g. The density of sunscreen cream is about 1g/cm3. A 50ml bottle of sunscreen cream weighs about 50g. It can be used on the face for 50/0.72≈70 days, which is about two and a half months. If the neck is also used, the amount needs to be increased by another 1/3, which is an increase of 0.24g. The amount for the hands, feet and other parts of the body will be even greater. As for sunscreen spray, its texture is quite different from that of sunscreen cream and cannot be simply calculated.

Do I need to use sunscreen after using cosmetics with SPF value?

It is recommended to use sunscreen. Although foundation, isolation and other cosmetics have sunscreen functions, there are requirements for the amount of sunscreen used. Generally, the amount of sunscreen used should be the size of a one-yuan coin, while the amount of cosmetics used is usually the size of a soybean. Simply relying on the SPF value in makeup products will have a very weak effect.

How to apply sunscreen when wearing makeup

1. Use oil-absorbing paper or cotton pad to absorb the grease and dust on your face.

2. Apply sunscreen product on facial skin and spread it gently and evenly with your hands.

3. Pat your skin with a powder puff to allow the skin to fully absorb the sunscreen product.

4. After applying sunscreen, you can apply other cosmetics to your facial skin.