That's an excellent and practical question! Finding the most cost-effective liner isn't just about the cheapest roll; it's about the perfect fit that minimizes waste and maximizes value. For a standard 50-gallon wheeled urban trash can, commonly used in public spaces, the most cost-effective liner size is typically a 48-gallon or 50-gallon trash bag.
Here’s the simple reasoning: A bag that's slightly smaller than the can's total capacity (like a 48-gallon bag for a 50-gallon can) fits snugly over the rim without excessive overhang. This prevents tearing from overfilling and reduces material waste from using an oversized bag. Using a correctly sized bag means every bag you purchase is fully utilized—no paying for unused cubic inches of plastic.
To be absolutely sure for your specific model, I recommend a quick measurement. Check the interior dimensions of your can. A liner that matches the can's depth and circumference will fit best. Bulk purchasing of the correct size from janitorial suppliers often offers the best long-term savings.
Ultimately, the most cost-effective liner is the one that fits your bin perfectly, reducing spillage, bag breakage, and unnecessary material cost. It’s a small detail that leads to cleaner spaces and smarter spending.