Carry-On Liquid Limit Calculator

How it is calculated

The tool applies two tests to the two numbers you enter, both in millilitres. First, the largest single container must be at most 100 mL: largest ≤ 100. Second, the total volume must be at most 1,000 mL, which the tool uses as a stand-in for what fits in the one quart-size bag of the US TSA 3-1-1 rule: total ≤ 1000. The status is "Within limit" only if both tests pass. It also shows the remaining allowance, 1000 − total, which stops at 0 mL when you are over, and whether the largest container is OK. A largest container bigger than the total is impossible, so that input shows no result; so do negative values. It cannot check items one by one, and rules differ between airports and countries.

Common mistakes

• Entering the amount of liquid left inside a container instead of the container's size. The 3-1-1 rule counts the labelled capacity, so a half-empty 200 mL bottle is still a 200 mL container.
• Entering ounces. Both fields are in millilitres, and 3.4 fluid ounces is the 100 mL limit, so convert a US travel bottle first to avoid a false result.
• Treating 1,000 mL as a hard rule. Security checks the bag size and the 100 mL container size, so the total is only a guide to what fits in the bag.
• Entering a largest container bigger than the total. That is impossible (150 mL largest with 50 mL total), and the tool shows no result until the numbers are consistent.
• Assuming a Within limit status clears security. Medical liquids, baby food and different airport rules are not modelled, and the tool says nothing about an individual product.