N+1 Capacity Calculator
The N+1 Capacity Calculator helps you determine whether a virtualization cluster can survive one or more host failures while still supporting the planned workload. Enter the number of hosts, tolerated failures, per-host CPU, memory, and storage capacity, along with your planned workload requirements and target utilization policies. The tool calculates surviving cluster capacity after host loss, applies your utilization limits, and compares the result against your workload demands. Results show a clear pass or fail status for each resource dimension — CPU, memory, and storage — along with headroom figures and progress bars. Presets for common cluster sizes let you model three-node, four-node, six-node, and dense cluster scenarios quickly. Advanced options include configurable utilization thresholds and optional storage capacity planning. This is a planning calculator; actual HA design also depends on admission control, anti-affinity rules, failover policy, storage architecture, and workload distribution. All calculations run entirely in your browser — no data is transmitted externally.