That's an interesting question that doesn't have a single simple answer, as urban trash cans vary quite significantly in weight depending on their design and materials. Generally speaking, a typical empty metal trash can you'd find on city sidewalks weighs between 30 to 50 pounds (14 to 23 kg). These standard steel receptacles are heavy by design to prevent tipping and withstand weather conditions.
However, many cities are now using lighter plastic models that might weigh only 15-25 pounds (7-11 kg) when empty. The weight difference comes from the materials - galvanized steel versus durable polyethylene plastic. Larger capacity bins obviously weigh more, with big concrete-embedded models in parks potentially reaching 80-100 pounds empty.
The specific design also affects weight - open-top baskets are lighter than enclosed containers with hinged lids. So while there's no universal standard, you can expect most standard city trash cans to fall in that 30-50 pound range when empty, with plastic versions at the lighter end and heavy-duty steel models at the higher end.