Free DevOps Tools

Handy calculators and utilities for sysadmins and DevOps engineers. No signup required.

Calculate allowed downtime for any SLA availability target from 99% to 99.999%.

Build and validate cron expressions visually with human-readable descriptions.

Plan server storage with growth projections and retention policies.

Calculate Mean Time To Recovery and compare against industry benchmarks.

Calculate network address, host range, and usable hosts from any CIDR notation.

Enter your load average and CPU cores to get a plain English explanation.

Need more than calculators?

FiveNines monitors your servers with real-time metrics, alerts, and dashboards.

Free tier includes 5 monitors - no credit card required

Looking for a monitoring tool? Read our guide to the best infrastructure monitoring tools in 2026.