The best sunscreen for you depends entirely on your skin tone and whether your skin generally is dry, oily, or neither. The sun protection factor, or SPF, number on each container of sunscreen tells you exactly how long you can stay out in the sun and remain protected from it. However, this is never listed in minutes or hours. These calculations are up to you.
Calculating Your SPF
If you want to know exactly how long your sunscreen protection will last, think about how long it takes you to get a sunburn when you are outdoors without any protection. The corresponding amount of time indicates how long you can aproximately stay safely in the sun before burning.
Fair skin - 10 minutes
Olive skin - 15 minutes
Dark skin - 20 minutes
Now look at the SPF on your sunscreen and calculate your protection time by multiplying the sun safety time for your skin type with the SPF listed on your sunscreen.
eg. 10 minutes (for fairskin) x SPF 20 = 200 minutes (3 hours) of sun protection. Although this seems to be an effective measue some studies show that these numbers aren't accurate if you are outdoors during the sunniest parts of the day.
To combat any problems with calculating your best sunscreen SPF, it is recommended that you use a sunscreen that has an SPF of at least 30. This should also have broad-spectrum protection against the sun's radiation. This protects not only from sunburn but also from the aging effects of sun exposure.
Your Skin Type
If you have oily skin and are prone to acne, you may have avoided sunscreen on your face because it will trigger breakouts. However, there are plenty of oil-free sunscreens on the market that will keep you protected without adding extra oil to your skin. Neutrogena is well known for its oil-free sunscreens, however there are also less expensive own brand options on the market.
If you have dry skin, there are other options. Nivea Moisturising Sun Spray is very effective at keeping skin hydrated as well as working as an effective sunscreen.