100ml is more than 3 ounces

Have you been told that you were restricted to carrying liquids in containers that hold no more than 3 ounces? After all, the TSA “3-1-1” policy includes “3” in its name, and it refers to the liquid weight you’re allowed to take with you in a single bottle.

…or is it?

If you go to the TSA’s Prohibited Items Web page (link), here is what it says:

3.4 ounces (100ml) or smaller container

Aha! So technically, you can actually carry more than 3 ounces! This is good news for folks who travel with toiletries from most of the rest of the world, which uses a metric measurement system, and whose toiletry bottles are often 100 milliliters in size.

But before you go decanting all your toiletries into 100ml bottles, though, beware. 3 ounces (or 3.4 ounces/100ml) is a really large bottle in the world of travel-sized toiletries. Unless you have an obsessive need to lotion your hands every 30 minutes, chances are you will not need such a large bottle. Or if you know you’ll use that much product, take 2 smaller bottles (2 ounces each, for example) and toss the bottles as you empty them out. That way your stuff will take up less room in your carry-on.

By the way, the Prohibited Items list has some pretty interesting tidbits on there. Did you know that you’re technically not allowed to take your gel insoles with you on the plane? Yep—the TSA is decidedly not gellin’ for Magellan!


  1. I bought FOUR OUNCE plastic bottles with flip top lids and have carried them to SE Asia , all over Europe and Canada and never got a second look from TSA . The TSA limit is 3.4 ounces. Nobody can tell the difference that extra .6 ounce in the size of my bottles but it means I never run out of shampoo

  2. I think most TSA agents can’t really tell the difference between a 100-ml and 4-ounce bottle, although I’ve heard from the occasional person who ran into a particularly strict security screener who either forced them to dispose of their bottles because it was a little over the limit, or because the bottles weren’t labeled. As long as you aren’t carrying a very exotic and hard-to-get shampoo in your 4-ounce bottle, and you’re OK with the risk of having them take it away, you might be in the clear!

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