You can usually bring liquids in containers up to 3.4 fl oz (100 ml) each , and all of them together must fit in one quart‑size clear zip‑top bag in your carry‑on.

Quick Scoop: How Many fl oz Can You Bring on a Plane?

For most flights in 2026, the standard TSA‑style rule is still the “3‑1‑1” liquids rule for carry‑on bags:

  1. 3 – Each liquid, gel, aerosol, cream, or paste must be in a container no larger than 3.4 fl oz (100 ml).
  1. 1 – All those small containers must fit inside one quart‑size (about 1 liter) clear resealable bag.
  1. 1 – You only get one such bag per passenger in your carry‑on.

So in practice:

  • The limit is 3.4 fl oz per container , not a fixed total number of ounces for all your liquids (as long as everything fits in that one quart bag).
  • A 4 fl oz bottle is not allowed in carry‑on, even if it’s only half full, because the container is too large.
  • In checked bags , there is usually no small‑bottle size limit for normal toiletries; only things like high‑alcohol liquids have volume caps.

Nuances and Newer Changes (2026)

A few wrinkles that are trending in 2026 travel:

  • Some UK airports (like Heathrow and Gatwick) now use advanced 3D scanners and have raised the liquid limit to up to 2 liters per container , letting you keep liquids in your bag at security.
  • However, this does not yet replace the 3.4 fl oz / 100 ml rule in most places , especially for typical TSA‑style checkpoints in the U.S.
  • Always check the departure airport’s security rules before you fly, because liquid rules are set by the airport/authority , not the airline.

An example: if you depart from Heathrow under the new system, you might carry a full‑size shampoo in your hand luggage; but if you connect through a country still using 100 ml rules and go back through security, it could be taken away.

What Counts as a “Liquid”?

Under these rules, the 3.4 fl oz cap usually applies to:

  • Drinks, soups, and sauces
  • Shampoos, conditioners, lotions, and liquid soaps
  • Toothpaste, gels, hair gel
  • Liquid makeup (foundation, liquid eyeliner, etc.)
  • Aerosols like hairspray or spray deodorant

Some items can break the 3‑1‑1 rule when properly declared and screened, such as:

  • Necessary medications in liquid form
  • Baby formula, breast milk, and baby food
  • Certain duty‑free liquids bought after the security checkpoint in tamper‑evident bags

These can often exceed 3.4 fl oz, but you usually must separate and declare them at security.

Quick FAQ (Carry‑On)

  • Q: So, exactly how many fl oz can I bring?
    A: Each container must be 3.4 fl oz (100 ml) or less , and all of them together must fit in one quart‑size clear bag in your carry‑on.
  • Q: Does it matter if my 4 fl oz bottle is only half full?
    A: Yes, it matters. The container size is what counts; a 4 fl oz bottle is generally not allowed in carry‑on, even if partially filled.
  • Q: Is there a limit in checked luggage?
    A: For normal toiletries, typically no strict small‑bottle limit in checked bags, though high‑alcohol liquids have quantity caps and over 70% ABV is banned.

Bottom line:
For a normal flight using standard security rules, pack liquids in containers up to 3.4 fl oz (100 ml) each and make sure everything fits in one quart‑size clear bag in your carry‑on.

Information gathered from public forums or data available on the internet and portrayed here.