Migrating Kubernetes clusters to Amazon EKS involves assessment, mobilization, and modernization phases, with cost estimation being a key challenge. Karpenter, an open-source autoscaler, and KWOK, a toolkit for simulating Kubernetes nodes, can help organizations optimize resource provisioning and estimate costs during this process without incurring actual infrastructure expenses. The article describes a method to simulate migrations and analyze Karpenter’s provisioning decisions to facilitate accurate cost estimations.