Honestly, there’s no single magic number, because it depends on how busy the park is, how large it is, and what facilities it has. But if I had to give a practical answer for a typical urban park with four entrances, I’d plan for around 16 to 20 trash bins as a baseline. A small, quiet neighborhood park might manage with 12 to 14, while a busy park with playgrounds, sports courts, picnic areas, restrooms, and event space could easily need 24 to 30 or more.
The entrance count gives you a useful starting point. Put at least one bin near each entrance, and on busier entrances, add a second bin just inside the gate. That already means 4 to 8 bins. Then place bins along the main walking loop roughly every 100 to 150 meters, and add extras at high-use spots: near benches, playground edges, restroom exits, sports courts, picnic shelters, dog areas, and food or gathering spaces.
So for a four-entrance park, I’d treat 16 to 20 bins as a sensible middle-of-the-road estimate. The bigger point is placement and servicing: a well-placed 16-bin system usually works better than 25 bins scattered randomly, especially if they are emptied often and clearly signed.