Taints and Tolerations Calculator
Calculate the number of nodes schedulable by a workload after accounting for tainted nodes and the tolerations it carries.
Inputs
Nodes carrying a NoSchedule/NoExecute taint (e.g. dedicated GPU or spot nodes).
Of the tainted nodes, how many this pod's tolerations allow it to be scheduled on.
Schedulable Nodes
36nodes
Effective Pod Capacity
720pods
Nodes Still Off-Limits
4nodes
Cluster Capacity Off-Limits
10.0%
Step by step
Schedulable nodes = total − tainted + tolerated
40 − 10 + 6
= 36
Capacity impact
36 × 20
= 720 pods
How it works
Taints repel pods from a node unless the pod carries a matching toleration, commonly used to reserve nodes for dedicated workloads (GPU nodes, spot/preemptible instances, specific teams). A given workload's schedulable node count is the untainted nodes plus whichever tainted nodes its tolerations unlock — nodes it neither avoids nor tolerates remain permanently off-limits to it.
Formula
schedulableNodes = (totalNodes - taintedNodes) + toleratedNodes
- N
- Total nodes in the cluster
- T
- Number of tainted nodes
- T_t
- Tainted nodes this workload tolerates
- S
- Nodes schedulable for this workload
Frequently Asked Questions
What's the difference between NoSchedule and NoExecute taints?
NoSchedule blocks new pods from being scheduled onto the node but doesn't affect pods already running there. NoExecute goes further — it evicts existing pods that don't tolerate the taint, in addition to blocking new ones.
Do tolerations guarantee a pod will be scheduled on a tainted node?
No — a toleration only removes the taint as a blocker; the scheduler still needs to independently decide to place the pod there based on other constraints like resource requests, affinity rules, and available capacity.
Why do cloud providers taint spot/preemptible node pools?
So only workloads explicitly designed to tolerate interruption (with a matching toleration) get scheduled there — this prevents critical stateful workloads from silently landing on cheaper but preemptible capacity.