That's a great question, and one that many people have when they get a new urban-style trash can. The short answer is: it depends entirely on the specific model you have.
Most modern urban trash cans, the kind you see on city streets and in public spaces, are designed to use standard-sized, heavy-duty liner bags. These are typically the large, black bags you can buy in rolls at any hardware or home goods store. They are made to be durable and resist tearing from sharp objects.
However, some models, especially newer or more specialized designs, might require a specific size or even a proprietary bag. The best way to know for sure is to check the manufacturer's instructions or the label inside the trash can lid. Often, the recommended bag size (like 55 gallons, 33 gallons, etc.) will be listed there.
If you don't have the manual, a simple test is to try fitting a standard large bag. If it seems too loose, bunches up at the bottom, or doesn't secure well around the rim, you likely need a different size. Using the wrong size bag can lead to messes—bags that are too small may tear, and bags that are too large are wasteful and difficult to secure.
For the most reliable and neat fit, I'd recommend measuring the interior dimensions of your can and comparing them to the bag specifications on the product roll. When in doubt, contacting the manufacturer or checking their website for your specific model number is always the safest bet to avoid any disposal headaches.