Right-Sizing vs. Auto-Scaling: Which Saves More on EKS?

Right-Sizing vs. Auto-Scaling: Which Saves More on EKS? Most EKS cost conversations end up in the same place: someone enables Cluster Autoscaler, watches the node count drop slightly, and calls it done. Then the bill barely moves. The reason is that Cluster Autoscaler and right-sizing solve different problems, and applying one without the other leaves most of the savings on the table. This piece breaks down what each approach actually does, where each wins, and in what order to apply them. The Billing Model That Makes Right-Sizing So Powerful EKS bills for EC2 node capacity, not for what your pods consume. A node is running, so you pay for it, regardless of whether pods use 10% or 90% of its resources. The waste happens at the request level. Kubernetes uses resource requests, not actual usage, to schedule pods onto nodes. When a pod requests 2 vCPU and uses 0.3 vCPU in practice, that 1.7 vCPU is reserved and unavailable for any other workload. The node fills up on paper while sitting m