Deployment Capacity Calculator
Calculate total serving capacity of a Kubernetes Deployment across its replicas.
About Deployment Capacity Calculator
Cluster-wide deployment capacity is bounded by node count multiplied by the effective pods-per-node ceiling (whichever of CPU, memory or kubelet max-pods binds tightest). Comparing current total replicas against that ceiling shows how much room remains before the cluster autoscaler needs to add nodes, or before pods start going Pending due to insufficient schedulable capacity.
Formula
maxPods = nodes × podsPerNode
- N
- Number of nodes in the cluster
- P_n
- Effective pods-per-node capacity
- P_{max}
- Maximum cluster pod capacity
Worked example
With the default values below, Deployment Capacity Calculator returns Max Cluster Pod Capacity of 300. Change any input above and every figure here is recalculated in your browser.
Inputs used
- Node Countaccepts 1–100,000 nodes
- 10 nodes
- Pods per Nodeaccepts 1–1,000 pods
- 30 pods
- Current Deployment Replicasaccepts 0–1,000,000 pods
- 120 pods
Results
- Max Cluster Pod Capacity
- 300 pods
- Current Utilization
- 40.0%
- Spare Capacity
- 180 pods
- Capacity Exceeded
- false
Step by step
- 1Max pods = nodes × pods per node= 300
- 2Current utilization= 40.0%
- 3Spare capacity= 180 pods
Assumptions and limits
- The result is derived only from the 3 inputs listed above. Anything not among them is not part of the calculation.
- In particular, this calculator does not take inflation, tax, fees or charges or compounding frequency into account.
- Figures are rounded for display to 1 decimal place, so totals built from several rounded parts can differ slightly from the unrounded arithmetic.
How these calculators are built and tested is described on the Methodology page. If a figure looks wrong, please report it.
Frequently Asked Questions
What utilization threshold should trigger adding nodes?
Most teams target 70-80% steady-state utilization, keeping 20-30% headroom for traffic spikes, rolling deployments and unscheduled pod restarts without waiting on cluster-autoscaler node provisioning time.
Does this account for DaemonSet and system pods?
No — subtract DaemonSet pods (CNI, log shippers, monitoring agents) per node from pods-per-node first, since they consume capacity on every node regardless of workload replicas.
How does this relate to the cluster autoscaler?
This calculator shows a static snapshot; pair it with the cluster autoscaler calculator to model how quickly new nodes come online once utilization crosses your scale-out threshold.