Honestly, there isn’t one magic number, but for most urban trash bins I’d aim for the opening to sit around 36–42 inches (about 90–105 cm) above the ground. That’s roughly waist-to-lower-chest height for many adults, so people can drop waste in without crouching or stretching. If I had to pick a sweet spot for a busy sidewalk, I’d go with about 36–38 inches (90–97 cm). It feels comfortable for most standing adults and works better for accessibility, including people with limited mobility and many wheelchair users who need a reasonable reach range.
The key is to measure to the actual opening or deposit slot, not just the total height of the bin. A tall decorative shell can still be awkward if the opening is too low or too high. Also think about how people use it: a simple drop-in opening can sit a little higher than a bin with a push flap, handle, or foot pedal. If people have to push or lift a lid, keep the motion easy and avoid sharp edges or tight gaps.
Context matters too. In a park or near a school, you might choose a slightly different height based on the main users, but I’d still avoid going below about 32 inches (81 cm) for a standard public bin because it encourages bending and makes the bin harder to use. Going above 42 inches starts to feel like a stretch for shorter adults and children. If the bin is dual-stream for trash and recycling, keep both openings at the same height and label them clearly at eye level so people don’t have to lean over to figure out where things go.
So, my practical answer: put the opening around 36–42 inches high, favor 36–38 inches for accessible public spaces, and test it with real people before installing a whole street’s worth. That small ergonomic choice makes a daily action feel a lot more natural.