Last checked: July 2026 — sourced against TSA “What Can I Bring?” and the TSA 3-1-1 liquids rule. Re-verify before you fly.
The verdict, in one line
Toothpaste is a paste, and TSA treats pastes as liquids. In a carry-on the tube must be 3.4 oz (100 ml) or less and fit in your quart bag. A full-size tube has to go in your checked bag, where there is no size limit.
Why toothpaste counts as a liquid
The 3-1-1 rule covers liquids, gels, aerosols, creams and pastes — containers of 3.4 oz (100 ml) or less, all fitting in one quart-size bag, one bag per passenger. Toothpaste is a paste, so TSA’s “What Can I Bring?” entry for toothpaste sends it straight to the 3.4 oz carry-on limit, right alongside shampoo and lotion. It doesn’t matter that you’d never squeeze out 3.4 ounces in a week; the checkpoint judges the container’s printed capacity, not how full it is.
This is the single most common travel-toiletry surprise: a standard drugstore tube is usually 4 to 6 oz, which is over the limit, so it gets pulled at the checkpoint even if it’s half used.
| Tube size | Carry-on | Checked bag |
|---|---|---|
| Up to 3.4 oz (100 ml) | Yes — in the quart bag | Yes |
| Standard 4–6 oz full size | No — over the limit | Yes |
| Toothpaste tablets (solid) | Yes — no limit, not a liquid | Yes |
How to pack it
Three clean options. First, buy a travel tube of 3.4 oz or less and put it in your quart bag with the rest of your liquids. Second, pack your big tube in your checked bag, where toothpaste has no size restriction. Third, switch to toothpaste tablets or powder — a solid form that isn’t covered by 3-1-1 at all, so you can carry as many as you want.
A common trick — decanting a full-size tube down to look “almost empty” — does not help. If the tube is labeled larger than 3.4 oz, expect it to be treated as oversized regardless of how much paste is left.
Flying from the UK, EU or elsewhere
The EU and UK apply the same 100 ml cabin limit to pastes, so toothpaste rules abroad mirror the US. The UK is transitioning: airports with new CT scanners — Heathrow, Gatwick, Edinburgh and Birmingham among them — now allow cabin liquid containers up to 2 litres, while Manchester, Stansted, Luton and others still hold the 100 ml line (Which?, 2026). Because a large tube cleared at a 2-litre airport can be refused on the return through a 100 ml airport, the reliable plan for any international trip is a travel-size tube in the cabin and the full tube checked.
And as always, the printed limit isn’t the last word: the TSA officer at the checkpoint has the final say on whether any item comes through.
Sources & verification
Every claim on this page was checked against the primary sources below and last verified July 2026.
- TSA — “What Can I Bring?”: Toothpaste (treated as a liquid/gel — carry-on tube must be 3.4 oz / 100 ml or less; larger tubes go in checked). tsa.gov/…/items/toothpaste
- TSA — Liquids rule (3-1-1 covers liquids, gels, aerosols, creams and pastes; checked bags have no liquid size limit; solids such as toothpaste tablets are not covered). tsa.gov/travel/security-screening/liquids-rule
- Which? — UK airport liquid rules: which airports allow 2 litres vs still enforce 100 ml (2026). which.co.uk — 100ml rule at UK airport security
Related rules: The 3-1-1 liquids rule · Deodorant on a plane · Water bottle on a plane
FAQ
Can I bring full-size toothpaste in my carry-on?
No. A standard 4–6 oz tube is over the 3.4 oz (100 ml) limit and must go in checked baggage. Use a travel tube in the cabin.
Does toothpaste really count as a liquid?
Yes. It’s a paste, and the 3-1-1 rule covers pastes, so it’s limited to 3.4 oz per container in a carry-on and must go in your quart bag.
My tube is nearly empty but says 6 oz — is that okay?
Usually not. The checkpoint goes by the container’s stated capacity, not how much is left, so an oversized tube can still be pulled.
Is there a limit on toothpaste in checked bags?
No. Full-size and multiple tubes are fine in checked baggage with no size restriction.
Do toothpaste tablets avoid the liquids rule?
Yes. Tablets and powder are solids, so they aren’t covered by 3-1-1 and you can carry any amount. The TSA officer still makes the final call.