What this metric is:
-    A rough estimate

-    An illustration of value Cloudflare provides

-    An assumption of your resource utilization 


The “fewer servers needed” percentage is a rough estimate of how much less capacity you need in order to handle your site’s traffic because you’re using Cloudflare. 


This number is based on the requests and bandwidth saved by Cloudflare.


We understand that each site is different in terms servers and arrangements with hosting providers, and that our numbers are not absolute. This metric is designed to help customers see how much web traffic Cloudflare is saving from going to your origin server.


These numbers can be used by customers who want to have discussions about cost-savings from using Cloudflare.


Example 1: If you are at 85% fewer servers needed, this means that Cloudflare is handling the majority of requests to your site, and you could be running your site using less hardware than you would without Cloudflare.


Example 2: If you are at 10% fewer servers needed, this means that the majority of your requests are going to your origin server directly. This means that without Cloudflare you need to add more hardware.


Learn how to get more value out of Cloudflare here:
What do the Cloudflare Cache responses mean?
How do I tell if Cloudflare is caching my files?
What extensions does Cloudflare cache by default?
What are Cloudflare's caching levels?
Does Cloudflare cache HTML?