Work out savings plan comparison instantly with clear inputs, formula shown and shareable results.
A savings plan discounts a committed hourly spend, so the blended discount is the headline rate multiplied by coverage. Committing 70 percent at a 28 percent discount yields only 19.6 percent overall — which is deliberate, because committing 100 percent of a variable workload guarantees paying for capacity you stop using.
Blended saving
committed = on-demand x coverage; new spend = committed x (1 - discount) + uncovered; effective discount = saving / on-demand
Commit to your reliable baseline, typically 60 to 80 percent of steady-state spend. Anything seasonal or growth-dependent should stay on demand or spot.
The extra discount is significant but so is the risk: architecture changes, instance-family shifts and workload migration over three years can leave the commitment stranded.