EC2 pricing glossary
The pricing models behind every number in this explorer, in plain English. If you are not sure whether you want a Reserved Instance, a Compute Savings Plan, or an EC2 Instance Savings Plan, start here.
On-Demand
Pay-as-you-go compute with no commitment — the baseline every other price is measured against.
Reserved Instance (RI)
A 1- or 3-year commitment to a specific instance type in exchange for a large discount off On-Demand.
Compute Savings Plan
A commitment to a fixed hourly spend ($/hr) that applies across instance families, sizes, regions, and even Fargate/Lambda.
EC2 Instance Savings Plan
A commitment to a specific instance family in one region, for a discount close to a Standard RI but with size flexibility.
Spot Instances
Spare AWS capacity at a steep discount — but AWS can reclaim it with two minutes’ notice.
Effective Coverage % (ECV%)
CloudQuell’s headline commitment metric: Coverage × Utilization — how much of your eligible spend is both committed and actually used.