When traveling by plane you’re only allowed to bring a quart-sized bag with various liquids with you in your carry-on baggage.

All these liquids must fit in containers for air travel that are 100 milliliters or less. Remember that all containers that are larger than 100 ml, regardless of the actual amount of liquid inside, must be placed in checked baggage.

Now you may be asking yourself: “Wait a minute, but how do I know how much 100 milliliters is? “Also, what does it look like, how much is it in ounces, and what  liquids can I pack in my carry-on?”.

Worry not – we are here to help you. We will answer all these questions below.

So, How Much Is 100 ML In Ounces?

So, 100 ml=3.4 oz.

100 ml is equivalent to 3.4 fluid ounces.

How Much Is 100 ML In Grams?

Converting milliliters to grams is super easy because the exact weight of 1 ml of water is 1 gram. And 100 ml=100 grams.

How Much Is 100 ML In Cups?

According to US standard sizes, one measuring cup equals 8 fluid ounces (if you are into cooking or baking, you might be well aware of it).

So 3.4 fluid ounces, or 100 ml, is less than 0.5 of one US measuring cup.

How Much Is It Visually?

What does 100 ml look like and what can it be compared to? Probably, one of the easiest ways to visualize 100 ml of liquid is to think of 2 mini-bar bottles of gin or whisky (these miniatures are 50 ml each). Or you could imagine a soda can (12 oz or 355 ml). In that case, one 100 ml bottle is less than one third of that can.

In any case, you can find toiletries for trips at any grocery store or drug store. They come in convenient 3-ounce (90 ml) containers. 

Travel Toiletries Containers And Bottles

If you are a frequent flyer, using special travel containers and bottles for liquid is more affordable than buying new travel-sized toiletries for each trip. Washing these containers after every trip and keeping them to use again in the future is cost-effective; in addition, this option is environment-friendly.

A set consisting of several small containers of different sizes is the ideal option.

What Liquids Can And Should Be Packed In Carry-On?

You may want to pack in your carry-on baggage your skincare, gels, pastes, lotions, and sprays to freshen up on the airplane or once you have arrived at your destination.

Here below are some of the liquids you might be planning on bringing with you.


A toothpaste is usually 100 ml. You could even get away with 110 ml toothpaste, as I did a couple of times. Not on purpose though.


An individual normally uses approximately 20 ml of mouthwash per cleanse, so a 3.4-ounce bottle of this product will only be enough for 5 uses. You should probably consider buying Listerine Ready tabs. They are solid, so you won’t have to worry about calculating how many ounces or ml of liquids you will be allowed to bring on the plane with you.

Body Wash And Shampoo

A person normally uses approximately 30 ml of body wash each time they take a shower. As for shampoo, it depends on hair texture and length. If it’s short, some people (especially men) might use as little as 10 ml per time.

Consider packing a soap bar in your hand baggage as an alternative to body wash. 

And remember that it makes no sense in packing 1 month’s worth of shampoo or shower gel if you are only going on a 2-day trip.

Deodorant Or Perfume

Bear in mind that there are no restrictions on stick deodorant or solid perfume size. But roll-ons, cream, gel deodorants, and perfume sprays are subject to the TSA rules, so if you want to bring those, you will have to put them in your zip-top quart bag. 

Just so you know, fragrance samples vary in size from 0.03 oz to 0.10 oz, or 1 ml to 3 ml. So if you can’t live without perfumes, it is a great idea to buy some samples and pack them in your carry-on baggage.

Liquid Make-Up

Some cosmetics count as liquids, and others do not. Compact or loose powder, as well as any make-up products that come in solid form, are allowed in carry-on in unlimited quantities.

Here are some make-up items that are considered liquid instead:

      • Primer
      • Foundation
      • BB cream
      • Concealer
      • Moisturizer
      • Creamy eyeshadow
      • Lip gloss
      • Mascara
      • Nail polish
      • Eyebrow gel.

So please remember that all these products are subject to the TSA rules and pack them accordingly.


If you’re going on a tropical vacation, you will definitely need sunscreen. Think carefully about how much of this product you will need on a daily basis. Usually, experts recommend putting one ounce of sunscreen on a person’s body and 0.04 ounces on the face.

Maybe, to worry less, it is worth buying sunscreen in your hotel or a shop once you have reached your destination. Consider this option.

Final Thoughts

We hope this article was helpful, and now you have gotten a good idea of how much 100 ml is and what it looks like. 

When you have proper travel containers, you can easily comply with the TSA liquid rules without exceeding the limit.

Bear in mind that you are only allowed to take one quart-size bag in your carry-on baggage – and that bag is not too big. If you use a flat 6×9 inch bag you can take about 6-7 travel containers. So think carefully about what you actually need.  

If you buy a 3-dimensional clear bag for toiletries, up to 10 travel-size 3 oz containers might fit into it.

However, if your trip is pretty long and you feel like you need to bring more toiletries, perfumes, or liquid cosmetics with you, consider checking in your baggage – it will make your life a lot easier.

About the Author


Content Manager & Editor

Maria became location independent in 2016 when she quit her job and became self-employed. She is currently exploring the world while working on her own projects. Email her at maria @ lifestyletraveler.co

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