How Much Suntan Lotion Do I Need For 2 Weeks?

sensuous slim woman applying suntan lotion on a beach vacation

How much suntan lotion do I need for 2 weeks? The answer here depends on a few different factors, like how long you plan to be out in the sun for, the frequency of application, and the size of the suntan lotion you are planning on bringing along. Also, you need to determine if others are going to be using the lotion as well.

After calculating all of these factors together, you should be able to figure out the approximate amount of suntan lotion you need for a 2 week trip. To learn more about how much sun lotion is needed for certain stretches of time, as well as if sunscreen is TSA-approved, continue reading below!

How Many Bottles Of Sun Lotion Do I Need For 2 Weeks?

As a general rule, you should use approximately 2 milligrams (mg) of sunscreen per square centimeter (cm²) of skin to achieve the Sun Protection Factor (SPF) reflected on a bottle of sunscreen. If you don’t, you will not get the full protection you need.

Food and Drug Administration (FDA) guidelines recommend you reapply sunscreen every two hours, and immediately after swimming. In order to stay sun-safe for six hours at the beach, you will need at least three applications of sunscreen, totaling 99mL per adult per day and 49.5mL per child per day.

For a 2 week vacation an adult would require 1,386mL (7 bottles) of sunscreen, likewise, a child would require 693mL (3.5 bottles). In reality, not many of us simply buy—let alone apply those quantities of sunscreen.

Also, Dr Anjali Mahto, consultant dermatologist recommends people to not spend all day, every day in the sun during their 2 week vacation, particularly not children. They should instead spend time in the shade under a tree, umbrella or other shelter between 10am and 4pm, wear protective clothing and a hat that protects their face, neck and ears.

Figuring out just how many bottles of sun lotion is needed for 2 weeks is not easy. Knowing where to start can feel impossible, especially when there are tons of other facets of the trip to sort out—things that are far more pressing than suntan lotion. 

Luckily, Julia Żuławińska and Aleksandra Zając of Omni Calculator have at least made the task digestible with their handy-dandy Sunscreen Calculator. All you need to do on your end is put in the requested information. The widget will then suggest how much lotion you should pack for 2 weeks.

It even has an option for face-specific lotion, because the amount of coverage to be expected is important to figuring out how many bottles will last 2 weeks and, as much as we could hope otherwise, there is a large difference between how much sunscreen goes on your face versus the amount used to appropriately cover your body. 

How Much Sunscreen Do I Need For 1 Week?

As a general rule, you need at least six full teaspoons of sunscreen to cover your face and body. According to Dr. Justine Hextall, a consultant dermatologist, for a 1 week vacation, you should pack at least 200 mL of sunscreen per person to protect your skin from the sun’s harmful rays. Depending on the type of travel, you will need more sunscreen.

How much sunscreen you need for a week wholly relies on how often you are planning to reapply, as well as the portion of time you are planning to spend outdoors during the week.

For example, if you only plan on being outside for 4 hours in the sun 3 days out of the week, then you do not need as much sunscreen as someone expecting to have 6 hours of sun exposure each weekday. 

Planning ahead is a vital step when it comes to figuring out how much sun lotion to pack. I would recommend trying to estimate your overall itinerary to better predict the amount of sunscreen you will need to stay protected. Also, it is always wiser to overpack than to underpack; if you would rather, a guesstimate wouldn’t hurt here.

How Long Will 8 Oz Of Sunscreen Last?

It would be a stretch to expect an 8 oz bottle of sunscreen to last more than 4 days. Generally, it is recommended to reapply sunscreen about every 2 hours, with an ounce projected to be applied each time.

If you are sunbathing for 4 hours, then you can expect to use at least 2 ounces a day, excluding the teaspoon amount that should be used for casual sun exposure.

There will be natural variations based on the individual which is why the Sunscreen Calculator in the previous section is so helpful: it takes the information provided to give a uniquely tailored recommendation. 

Keep in mind that the American Academy of Dermatology Association states that an ounce of sun lotion is enough to cover an adult’s body, so that variable will be static when determining how long a bottle of sunscreen will possibly last.

How Long Will 50mL Sunscreen Last?

A bottle of 50 mL sunscreen should last 3-4 weeks, or a month and a half, with regular application. Since a teaspoon is roughly equal to 1.23 mL, 50 mL sunscreen will certainly last you for some time. Really, the size of this sunscreen is no joke! 

In case you were at all worried about not being able to use up a 50 mL bottle of sun lotion before then, the good news is that sunscreen can be effective for up to 3 years after opening.

So, 50 mL sunscreen can last you quite a while if you are not planning on sitting out in the sun consistently each day, or for periods of time not long enough to warrant reapplication. 

How Long Is SPF 30 Good For?

As with other sun lotions, 30 SPF needs to be reapplied every 2 hours. For sunscreen to remain effective, it needs to be regularly reapplied regardless of the quoted Sun Protection Factor. Otherwise, it will lose its protective qualities over time.

Generally speaking, SPF between 30 and 50 is recommended by dermatologists universally for skin protection. Part of this is because 30 SPF protects against about 97% of UVB rays, while 50 SPF guards 98%.

It is believed that UVB radiation is the leading cause of skin cancer development—it is also the type of ultraviolet ray that causes sunburns! So, more or less, the greater protection you have against UVB, the better it is for your skin.

Is Sunscreen TSA Approved?

Absolutely! Sunscreen is approved by the Transportation Security Administration (TSA) in both spray and lotion forms. Despite some misunderstandings in 2021, the TSA clarified that sunscreen was not deemed a medically necessary liquid. That being said, all sunscreen must comply with the 3-1-1 Liquids Rule.

To put it simply, the 3-1-1 Liquids Rule means that anything that is 100 mL or less can be in a carry-on (as long as the container in turn can fit in a resealable quart-sized bag). And, as you could probably guess, anything larger than that has to be in checked baggage. 

Final Thoughts: How Much Suntan Lotion Do I Need For 2 Weeks?

With all of this in mind, remember most of all that it is crucial to prepare ahead for sun exposure. Not only are sunburns nasty to deal with, but they are simply painful and can heighten your risk of developing skin cancers through damaged cells. 

This being said, try to figure out how long you are planning to sunbathe for, and pack accordingly. Packing too much sunscreen rather than too little is far better than finding yourself stuck without proper protection.

Also: please, reapply whatever SPF sunscreen you are wearing at least every 2 hours you are in the sun! Whether it’s enough to just cover your arms, neck, and face, or more to cover your entire body, reapplication is key to avoid any lasting sun damage.

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By Cierra Tolentino

Cierra Tolentino is a beauty writer at Kintegra Research. She loves keeping people up-to-date with the latest beauty trends in skincare, hair care, and makeup. Finding answers to tough questions is her thing. When she has free time you can find her chasing down a clumsy toddler and obsessively drinking tea.