AWS · Free tool
AWS CloudWatch Logs cost calculator
Plug in monthly log ingest, retention, and query patterns. The calculator shows the ingestion line, storage tail, Logs Insights queries, and the savings from cutting retention or moving cold logs to S3.
Monthly CloudWatch Logs bill
Total / month
$0
Ingestion
$0
Storage tail
$0
Logs Insights
$0
Annualized
$0
12 months at this rate.
Retention savings scenarios
- Adjust retention above to see scenarios.
If the bill is bigger than expected, check these
- VPC Flow Logs in full mode logging accept and reject.
- Log groups with no retention policy.
- Lambda functions writing console.log on every invocation.
- CloudFront real-time logs sent to CloudWatch instead of Firehose to S3.
Why CloudWatch Logs grows quietly
New log groups default to indefinite retention. Every group created without `retention_in_days` keeps data forever, and storage at $0.03 per GB per month becomes material once old logs reach terabytes.
VPC Flow Logs in full mode log every accepted and rejected packet. A medium VPC can generate 1 to 3 TB of Flow Logs per month, usually queried only a few times per quarter.
The fix is mechanical: run `aws logs describe-log-groups`, sort by stored bytes, identify the no-retention long tail, and apply 14 or 30 days where long history is not required.
Run this on your real account
Free 14-day audit, read-only IAM role, one-page CFO summary.
We pull every log group, sort by stored bytes, identify the no-retention long tail, and hand engineering the exact retention policy to apply.
Frequently asked
Why is CloudWatch Logs so expensive?
Three lines stack together: ingestion at $0.50 per GB, storage at $0.03 per GB per month, and Logs Insights queries at $0.005 per GB scanned. VPC Flow Logs in full mode usually create the largest surprise.
What is the default retention for a new log group?
Never expire. AWS does not set a retention policy on new log groups, so every group created without explicit retention keeps data forever and pays storage indefinitely.
Can I export old logs to S3 and stop paying CloudWatch storage?
Yes. CloudWatch Logs supports export-to-S3 tasks. S3 Standard and Glacier Instant Retrieval are cheaper for audit-grade retention, but you lose Logs Insights querying on that old data.
How do I find the log groups driving the bill?
Run aws logs describe-log-groups and sort by storedBytes. The top five log groups usually explain most of the bill, especially accounts with /aws/vpc/flowlogs in full mode.
Related free tools
Keep going. No email.
AWS · Networking
NAT Gateway cost calculator
The line item nobody budgets for. Hourly cost, data-processing cost, monthly total, and a checklist of the most common NAT cost drivers we catch in audits.
AWS · Commitments
Reserved Instance break-even calculator
Standard or Convertible, 1 or 3 year, every payment option. Monthly savings, break-even month, net return over the term. Defaults you can override with your real EDP rate.
AWS · Commitments
AWS Savings Plan ROI calculator
Plug in your on-demand spend, commit term, and payment option. Get monthly savings, break-even month, and net return over the term. Honest about the assumptions, no email gate.