Bandwidth is a crucial factor to consider when choosing a web host, as excessive traffic can lead to slower load times, website crashes, or overage fees. To calculate bandwidth usage, developers must estimate page weight, average pageviews per day, and downloadable content. A simple equation calculates the required bandwidth by multiplying these factors with a redundant factor of 1.5. Optimizing for bandwidth involves reducing page weight through image optimizations, caching settings, lazy loading images, and monitoring optimizations. Some web hosts, like Netlify, offer increased bandwidth limits in their plans to minimize overage fees.