The 3.4 oz Carry-On Liquid Limit
Carry-on liquids must be in containers of 3.4 fl oz or 100 mL or less. The size printed on the container counts, not what is left inside.
Key facts
- Limit per container
- 3.4 fl oz or 100 mL, either figure
- 3.4 US fl oz in mL
- 100.55 mL
- 100 mL in US fl oz
- 3.38 fl oz
- US bag
- One quart-size clear bag (946.35 mL) per traveler
- Allowed in larger amounts
- Medicine, baby formula and breast milk, declared at the checkpoint
Check a container
Pass. Within the 3.4 fl oz / 100 mL container limit.
The rule reads the size printed on the container, not how much is left inside.
Common sizes against the limit
| Printed size | mL | US fl oz | Result |
|---|---|---|---|
| 1 fl oz | 29.57 | 1 | Pass |
| 2 fl oz | 59.15 | 2 | Pass |
| 3 fl oz | 88.72 | 3 | Pass |
| 3.4 fl oz | 100.6 | 3.4 | Pass |
| 3.5 fl oz | 103.5 | 3.5 | Over the limit |
| 5 fl oz | 147.9 | 5 | Over the limit |
| 50 mL | 50 | 1.69 | Pass |
| 100 mL | 100 | 3.38 | Pass |
| 101 mL | 101 | 3.42 | Over the limit |
| 150 mL | 150 | 5.07 | Over the limit |
Each row is checked in the unit it is printed in, the way the rule reads it.
Worth knowing
The rule has two numbers because it has two origins. 100 mL is the limit used in the EU and UK. The US writes it as 3.4 oz, which is 100.55 mL, a hair over 100. A container that says either figure passes. That is also why a 3.5 oz bottle fails: it is over 3.4, even though a bottle marked 100 mL, which is a little smaller, passes.
What counts is the capacity printed on the container. A 5 oz bottle with 1 oz left is still a 5 oz container and does not pass. Refillable travel bottles should have their size marked on them. Gels, creams, pastes, sprays and aerosols count as liquids, and solids such as stick deodorant and bar soap do not. Some airports with newer scanners relax the limit, and rules change, so check your airport and airline.
Questions
Is 3.4 oz the same as 100 mL?
Close enough that the rules treat them as the same. 3.4 US fl oz is 100.55 mL, and 100 mL is 3.38 US fl oz.
Does a half-empty 6 oz bottle pass?
No. The limit reads the container size, not the contents. A 6 oz bottle with 2 oz left is still over 3.4 oz. Move the liquid into a bottle marked 3.4 oz or smaller.
Does a 3.5 oz bottle pass?
Not if it is labeled 3.5 oz, which is 103.5 mL and over the limit. A bottle labeled 100 mL passes.
Does the limit apply to checked bags?
No. The 3.4 oz limit is for carry-on bags. Airlines still restrict some items in checked bags, such as certain aerosols and flammables.