Why this matters

Toothpaste is one of the most commonly confiscated items at airport security, purely because travelers do not think of a paste as a liquid. Security does: anything spreadable or squeezable falls under the liquids rule. A standard family-size tube is 4–6oz, comfortably over the carry-on limit, so the default tube in most bathrooms cannot fly in the cabin.

The fix costs a couple of dollars — a travel-size tube — but only if you know the rule before you reach the checkpoint.

Restrictions

In carry-on baggage, toothpaste follows the 3-1-1 liquids rule:

  • The tube must be 3.4oz (100ml) or smaller, going by the size printed on the packaging.
  • It must fit inside your one quart-size clear bag along with all other liquids and gels.
  • A partly used larger tube still fails — container size is what counts.

In checked luggage there is no restriction: full-size tubes, multipacks, and any quantity reasonable for personal use are all fine.

Solid alternatives — toothpaste tablets, powders, and chewable tabs — are not liquids and travel without limits in either bag. The same logic applies to a dry toothbrush and dental floss, which are unrestricted.

These rules are consistent worldwide: the 100ml cabin standard applies in the US, EU, UK, Australia, and virtually everywhere else, making toothpaste one of the few items where one packing habit works globally.

What the official guidance says

TSA lists toothpaste as a carry-on item subject to the 3-1-1 rule — containers of 3.4oz or less in a single quart-size bag — and places no limit on checked baggage. The guidance notes that officers can ask for any item to be screened separately, and oversized tubes found in carry-on bags are surrendered at the checkpoint rather than returned.