Kubernetes requests & limits: practical sizing

Scheduling is based on requests. That’s why most capacity planning starts with requests and then uses limits to reason about burst and risk.

1) Requests drive node count

A simple approach: total requests = pods × per-pod request. Then divide by allocatable per node. Our calculator does that and takes the larger of CPU-based and memory-based counts.

2) Leave allocatable headroom

Nodes aren’t 100% allocatable. System overhead, daemonsets, and kubelet reservations reduce usable capacity. Planning with 85–95% allocatable is common depending on your environment.

3) Limits matter for burst behavior

• CPU limits can throttle bursts.
• Memory limits can lead to OOM kills if pods exceed limits.

Tool

Kubernetes requests & limits calculator