EC2 instances averaging 10–40% CPU over 14 days — review for right-sizing

AWSCost optimizationFree planSeverity: mediumaws.ec2

Running EC2 instances (≥14 days old, not T-family burstable, not tagged RightSized) whose 14-day average CPU is between 10% and 40%

What LeftSize checks

Find underutilized EC2 instances with low but non-zero CPU usage (right-sizing candidates)

Why it matters

Resources like this keep billing every hour while delivering little or no value, and nobody notices until the invoice arrives.

What you get in the GitHub issue

LeftSize runs this check from a scheduled GitHub Action with a read-only identity in your AWS account and opens one issue per scope, updated on every scan. The issue includes:

  • The affected resources, grouped per subscription, resource group or account and region
  • An estimated monthly cost where pricing data is available
  • Background on why it was flagged and when it is a false positive
  • Cost and operational impact of fixing it
  • Alternative approaches and their trade-offs
  • Step-by-step remediation with safety checks
  • Ready-to-run fix scripts (CLI, PowerShell or Terraform where available)
  • Snooze, ignore or report a finding with a comment on the issue
Install LeftSizeIncluded in the Free plan.