Cloud Reserved Instance Savings Forecaster
Estimate whether committing to cloud reserved instances saves money versus staying on demand. Enter on-demand and reserved hourly rates, expected hours per month, utilisation, and the term length to see the absolute and percentage savings.
CalcSimpler Examples
- $0.34 on-demand, $0.21 reserved, 730 h/month, 85% use, 12 months ⇒ Savings: $692.04 (27.3%)
- $0.40 on-demand, $0.32 reserved, 600 h/month, 60% use, 36 months ⇒ Loss: $1,728.00 (-33.3%)
FAQ
Does utilisation include seasonal spikes?
Yes. Enter the average percentage of committed hours you expect to use across the term.
How do upfront fees factor in?
Add the amortised upfront payment to the reserved hourly rate before entering it to capture true costs.
Can I compare multi-cloud offers?
The calculation is agnostic—enter the corresponding rates for AWS, Azure, or Google Cloud and compare scenarios.
Additional Information
- On-demand spend is scaled by utilisation, while reserved spend assumes you pay for all committed hours.
- Negative savings indicate you are overcommitting relative to actual usage.
- Revisit utilisation assumptions quarterly to keep projections accurate.
CalcSimpler