devops/calculator
K8s Resource & Sizing Calculator - Free & Instant | Smocky
Frequently asked questions
Why are nodes sized from requests rather than limits?
The Kubernetes scheduler places a Pod by its CPU and memory requests. Limits cap what a running container may use, so this calculator reports their totals separately and never adds nodes for them. A limit total is marked incomplete when any Pod sets no limit for that resource.
What should Node overhead include?
Node overhead is the CPU and memory set aside on every node for system and kubelet reservations, the eviction reserve, and DaemonSet requests. Enter those DaemonSets here only, not again as Pod groups. What remains is Workload capacity, which can be smaller than Kubernetes Node Allocatable because it also excludes DaemonSets.
Why is the estimate higher than total requests divided by node size?
A Pod cannot span nodes. Four Pods requesting 3 cores each need four nodes with 4 usable cores, although dividing 12 cores by 4 suggests three. The calculator places each Pod on the first node with room for both its CPU and memory, largest first.
Is Estimated nodes a guarantee?
No. It is an estimate from first-fit decreasing placement, not a proven minimum or a simulation of the Kubernetes scheduler. Affinity, taints, topology spread, Pod-count limits, and a reserve for node failure are not modelled.
What does headroom mean here?
Request headroom is Workload capacity that no Pod requests, per node and across all estimated nodes. It is not measured usage and does not promise room for bursts above requests.
What does the monthly cost include?
Only Estimated nodes multiplied by the monthly price per node you enter, in that same currency. It does not fetch prices, convert currencies, or include storage, load balancers, egress, or control-plane charges.