StatefulSet Capacity Calculator
Calculate storage and compute requirements for a StatefulSet's ordered replicas.
About StatefulSet Capacity Calculator
Each StatefulSet replica gets its own PersistentVolumeClaim via volumeClaimTemplates, so total storage scales linearly with replica count. By default StatefulSets use the OrderedReady pod management policy, starting pods one at a time and waiting for each to become Ready before starting the next — which means full startup time scales linearly with replica count too, unless podManagementPolicy is set to Parallel.
Formulas
Total storage
totalStorage = replicas × pvcSize
- R
- Number of StatefulSet replicas
- V
- PVC size per replica in GiB
- S
- Total persistent storage in GiB
Startup time
startupTime = parallelPodManagement ? podStartup : podStartup × replicas
- t_p
- Per-pod startup time in seconds
- R
- Number of replicas
- T
- Total startup time in seconds
Worked example
With the default values below, StatefulSet Capacity Calculator returns Total Persistent Storage of 500.0. Change any input above and every figure here is recalculated in your browser.
Inputs used
- Replicasaccepts 1–10,000 pods
- 5 pods
- PVC Size per Replicaaccepts 0.1–1,000,000 GiB
- 100 GiB
- Per-Pod Startup Timeaccepts 1–36,000 seconds
- 45 seconds
- Parallel Pod Management
- No
Results
- Total Persistent Storage
- 500.0 GiB
- Full StatefulSet Startup Time
- 3.8 minutes
- Startup Time
- 225 seconds
Step by step
- 1Total storage = replicas × PVC size= 500.0GiB
- 2Startup time= 225s
Assumptions and limits
- The result is derived only from the 4 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
Why does StatefulSet startup take so much longer than a Deployment's?
Deployments start all replicas concurrently by default. StatefulSets default to OrderedReady, which is deliberately sequential — this preserves a strict identity/ordering guarantee (pod-0 before pod-1, etc.) that ordered clustered systems like ZooKeeper or Kafka rely on during bootstrap.
When is it safe to use Parallel pod management?
When your application doesn't depend on strict startup ordering for cluster formation — e.g. it handles peer discovery independently. Databases with leader election or ordered bootstrap sequences usually require OrderedReady.
Does scaling down also happen in reverse order?
Yes — with OrderedReady, pods are terminated in reverse ordinal order (highest first), and PVCs are retained by default (not automatically deleted) unless you configure a persistentVolumeClaimRetentionPolicy.