Reserved vs On-Demand Calculator
Compare total costs between reserved and on-demand cloud instances. Calculate savings percentage and break-even analysis for your commitment period.
How to Use the Reserved vs On-Demand Calculator
- Enter on-demand hourly price.
- Enter reserved hourly price.
- Enter monthly hours of operation.
- Enter commitment term in months.
- Click Calculate to compare costs.
Use Cases
- •Deciding whether to purchase reserved instances.
- •Calculating break-even for reserved commitments.
- •Presenting cloud cost savings to management.
- •Optimizing cloud spend for steady-state workloads.
Formula
On-demand total = hourly rate × hours × months. Reserved total = reserved rate × hours × months. Savings = (OD − Reserved) / OD × 100%.
Frequently Asked Questions
How much can reserved instances save?
Reserved instances typically save 30–70% versus on-demand, depending on term length and payment option.
What is the commitment period?
Cloud providers offer 1-year and 3-year reserved terms. Longer terms provide greater discounts.
What if my usage drops?
Reserved instances are billed regardless of use. Only reserve capacity you're confident you'll use continuously.