You can only bring small amounts of liquid in your carry-on, and it all has to fit in one clear bag that goes through security with you.

The basic 3-1-1 rule (US & many other countries)

Most airports that follow TSA-style rules use the 3-1-1 guideline for carry-on liquids, gels, creams, pastes, and aerosols.

  • “3” – Max size per container:
    Each container must be 3.4 ounces (100 ml) or less.
* A 4 oz bottle is _not_ allowed in carry-on even if it’s half empty.

* The rule applies to things like shampoo, conditioner, lotion, perfume, liquid makeup, toothpaste, and many food items (sauces, yogurts, peanut butter-like textures).
  • “1” – Bag size:
    All your liquids must fit into one quart-sized (about 1 liter) clear, resealable plastic bag.
* The bag has to close fully (no overstuffing).
* Roughly, people fit about **5–10 travel bottles** in there, depending on shape.
  • “1” – One bag per person:
    Each passenger gets one such liquids bag in their carry-on.

So in practice, the limit is not a specific “total ounces” but:

As many 3.4 oz (100 ml) containers as you can comfortably fit in one quart-sized clear bag , with a maximum of 3.4 oz per item.

What doesn’t count against the limit?

Some items are treated differently and can exceed 3.4 oz in your carry-on, though you usually must declare them and may get extra screening.

Common exceptions (rules can vary by country/airport, so always check your specific airline/authority):

  • Medications (liquid prescriptions, certain medical liquids).
  • Baby items (formula, breast milk, baby food in reasonable quantities for the journey).
  • Special dietary needs (sometimes allowed in larger amounts with explanation).

Airport duty-free liquids bought after security (e.g., perfume, alcohol) can usually be larger than 3.4 oz as long as they’re in secure, tamper-evident packaging and kept sealed until you reach your final destination or connecting airport rules allow.

What about checked luggage?

Your checked bags are much less restricted for most everyday liquids.

  • You can generally pack full-size bottles (shampoo, body wash, etc.).
  • There are still limits on some items like alcohol and aerosols (for example, in the US, alcohol between 24% and 70% ABV is capped at 5 liters per person in checked baggage, and very high-proof alcohol is banned).

Quick packing tips

To make the 3-1-1 rule easier to live with:

  • Use travel-size bottles (under 100 ml) and refill from your large bottles at home.
  • Put all liquids in your quart-sized bag at home so you can just pull it out at security.
  • Tighten caps firmly, and if you’re worried about leaks, add a piece of plastic wrap under the cap or a bit of tape.
  • Consider solid versions of toiletries (bar shampoo, bar soap, solid perfume, stick deodorant) to save your liquid allowance.

Mini example: how much can you really bring?

Imagine you have:

  • 1 × 100 ml shampoo
  • 1 × 100 ml conditioner
  • 1 × 100 ml body wash
  • 1 × 100 ml face wash
  • 1 × 50 ml moisturizer
  • 1 × 30 ml perfume

If they all fit and the quart bag can fully close , you’re fine, because each container is ≤100 ml and they all fit in a single quart bag.

Bottom line: for a carry-on, think “small bottles (3.4 oz / 100 ml or less), all in one clear quart-sized bag, one bag per person.” Anything more belongs in checked luggage or should be bought after security.

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