13 Hip Flask Sizes in oz and ml (Updated for 2026)
Compare 13 hip flask sizes from 1 oz to 64 oz in milliliters, with how many standard drinks each holds and which fit a carry-on.
The table below runs from a tiny 1 oz flask up to a 64 oz giant, and every US fluid ounce equals 29.5735 milliliters1. A 6 oz flask holds 177 ml, enough for four standard drinks. An 8 oz flask holds 237 ml, and that pours a little over five.
All 13 sizes in ounces and milliliters
| Flask size | Milliliters | Drinks at 1.5 oz | Pours at 1 oz | Under 100 ml |
|---|---|---|---|---|
| 1 oz | 30 ml | 0.7 | 1 | Yes |
| 2 oz | 59 ml | 1.3 | 2 | Yes |
| 3 oz | 89 ml | 2 | 3 | Yes |
| 4 oz | 118 ml | 2.7 | 4 | No |
| 5 oz | 148 ml | 3.3 | 5 | No |
| 6 oz | 177 ml | 4 | 6 | No |
| 8 oz | 237 ml | 5.3 | 8 | No |
| 10 oz | 296 ml | 6.7 | 10 | No |
| 12 oz | 355 ml | 8 | 12 | No |
| 16 oz | 473 ml | 10.7 | 16 | No |
| 18 oz | 532 ml | 12 | 18 | No |
| 32 oz | 946 ml | 21.3 | 32 | No |
| 64 oz | 1,893 ml | 42.7 | 64 | No |
Each row multiplies the ounces by 29.5735 and rounds to the nearest whole milliliter. The last column marks flasks that hold 100 ml or less, the limit for alcohol in a carry-on.
How ounces turn into milliliters
The US fluid ounce is defined in NIST's table of conversion factors as 29.57353 milliliters1. To convert any flask, multiply its ounces by that number. For an 8 oz flask, 8 × 29.5735 is 236.6, and that rounds to 237 ml.
Going the other way, divide the milliliters by 29.5735. A flask labeled 500 ml is 16.9 US ounces, so it sits between the 16 oz and 18 oz rows of the table.
How many drinks fit in each size
The National Institute on Alcohol Abuse and Alcoholism counts a 1.5 oz shot of 40% spirits as one standard drink2. So to find the number of drinks, divide the flask size by 1.5.
An 8 oz flask gives 5.33, which means five full drinks and a little left over. A 6 oz flask gives exactly four, and a 12 oz flask gives exactly eight. The third column in the table shows the rest, and it assumes you pour a full 1.5 oz each time.
Smaller pours stretch a flask further, because a 1 oz splash is two thirds of a standard drink. At that size an 8 oz flask pours eight times. Check the cups that come with your flask against a measuring jigger before you count on any number.
Which sizes pass through airport security
When you fly, the FAA's alcohol rules limit liquids in a carry-on to 100 ml, or 3.4 oz, per container3. In the table, only the 1, 2 and 3 oz flasks come in under that line. A 4 oz flask holds 118 ml, so it is already over.
The same page says checked spirits between 24 and 70 percent alcohol have to travel in sealed bottles from the store3. A flask you filled yourself does not fit that description, so the safest plan is to carry it empty and fill it after you land. If the funnel stays home, these tricks for topping up a flask without one will get you through.
Reading a 500 ml or a British listing
A 500 ml flask is 16.9 US ounces, so it holds eleven drinks at 1.5 oz and a bit of room to spare. A flask listed in milliliters is easy to compare, because you can find its row in the table by that number.
Be careful with ounces on a British listing, because the imperial fluid ounce is a little smaller. NIST puts the imperial ounce, still used in the UK and Canada, at 28.41 ml1. So if a British maker counts in imperial ounces, a 6 oz flask holds about 170 ml, while a US one holds 177 ml.
The 8 oz flask we make
Our leather flask holds 8 oz, so it pours five drinks at the standard 1.5 oz size. The listing describes a 304 stainless steel body under smooth PU leather. The box also holds a funnel and a pair of small pony glasses, all inside a wooden case4. To see how a size sits in a pocket, read our piece on where to carry a flask and which way the curve should face.
Size is only half of the choice, because the drink changes how much you want to carry. Our guide to what goes in a hip flask covers the options, and the main hip flask guide covers the rest.
Hip flask size questions, answered
How many ounces does a hip flask hold?
That depends on the model, and the table above covers sizes from 1 oz up to 64 oz. For example, a 6 oz flask holds 177 ml and an 8 oz flask holds 237 ml.
How many shots are in an 8 oz flask?
An 8 oz flask holds 5.33 shots when each shot is the standard 1.5 oz2. In practice you will pour five full shots and have a small splash left over.
Is a 500 ml flask the same as a 16 oz flask?
Not quite, because 500 ml is 16.9 US ounces. A 16 oz flask holds 473 ml, so the metric one is a little bigger.
Can a hip flask go in a carry-on bag?
The flask itself can, but the FAA limits any alcohol inside it to 100 ml per container3. Only the 1, 2 and 3 oz sizes stay under that limit.
Sources
- 1.National Institute of Standards and Technology (NIST), NIST Guide to the SI, Appendix B.8: Factors for units listed by kind of quantity or field of science. Checked 27 Oct 2026.
- 2.National Institute on Alcohol Abuse and Alcoholism, What is a standard drink? Checked 27 Oct 2026.
- 3.Federal Aviation Administration, PackSafe: Alcoholic beverages. Checked 27 Oct 2026.
- 4.Excalibur Brothers, Men's Leather Flask (Brown) with 2 Cups and Funnel. Checked 27 Oct 2026.