Compute Instance Cost Calculator

For back-of-the-napkin budgeting, instance count x hourly price x billable hours gets you most of the way. Compare baseline vs peak instance counts with a simple utilization model.

Inputs

Instances
Price ($ / hour)
~$131.33 per month at 24x30.4.
Utilization (%)
Use 100 if hours/day already models uptime.
Hours/day
Use 24 for always-on workloads.
Days/month
Use 30.4 for an average month.
Monthly hours: 730
Scenario presets

Results

Estimated monthly compute cost
$787.97
Billable hours (per instance)
730 hr (100%)
Cost per instance
$131.33
Billable hours (fleet)
4,378 hr

How to get your inputs

  • Instances: use average running instances from billing (instance-hours / monthly hours), not peak.
  • Hourly rate: use a blended effective $/hour if you mix on-demand, commitments, or spot.
  • Schedule: set hours/day and days/month from real uptime windows or automation schedules.

Result interpretation

  • Instance count and billable hours are the core drivers.
  • Peak scenarios show autoscale risk; compare baseline vs peak for capacity planning.

Common mistakes

  • Using peak instance count as baseline and overestimating spend.
  • Applying both utilization and reduced hours/day for the same schedule (double discount).
  • Ignoring minimum autoscaling capacity that runs 24/7.

Scenario planning

Scenario Instances Hours/day Utilization
Baseline Average Normal Typical
Peak High Same Same

Validate after changes

  • Compare instance-hours and effective $/hour to the first real bill and adjust.
  • Verify average instance count with metrics or inventory data.

Next steps

Guides All calculators Reserved break-even Kubernetes node cost RPS to monthly requests
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Example scenario

  • 6 instances at $0.18/hour running 24/7 -> estimate monthly compute cost.
  • Peak 200% scenario captures seasonal scale-out.

Included

  • Monthly compute estimate from instance count, $/hour, and billable hours.
  • Days/month input to align with billing cycles.
  • Utilization inputs for schedules and non-24/7 environments.
  • Baseline vs peak scenario table for scale-out.

Not included

  • Storage, bandwidth, managed service fees, and taxes.
  • Autoscaling behavior and per-second billing nuances.

How we calculate

  • Billable hours per instance ~ days per month x hours/day x utilization.
  • Monthly cost = instances x billable hours per instance x $/hour.
  • Use 30.4 days/month for an average month or set the exact billing month.
  • This tool excludes storage, bandwidth, and managed service surcharges.

FAQ

What should I use for utilization?
Use 100% for always-on workloads, or a lower percentage for schedules or dev/test environments.
How do I include committed discounts?
Use your effective $/hour after discounts (or model break-even using the reserved vs on-demand tool).

Related tools

Reserved break-even Kubernetes node cost RPS to monthly requests

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Disclaimer

Educational use only. Not legal, financial, or professional advice. Results are estimates based on the inputs and assumptions shown on this page. Verify pricing and limits with your providers and documentation.

Last updated: 2026-01-29