Calculate service availability percentage from total time and downtime. Verify SLA compliance and track uptime performance metrics.
Service Level Agreements (SLAs) define availability commitments between providers and customers. This calculator determines your actual availability percentage based on total operational time and observed downtime, then compares it against your SLA target.
Whether you're an SRE tracking monthly availability, a vendor preparing compliance reports, or a customer auditing provider performance, this tool gives you precise availability metrics. Enter your downtime in minutes and the measurement period to get an instant availability percentage with SLA pass/fail assessment.
Precise measurement of this value supports informed infrastructure decisions and helps engineering teams optimize system architecture for both performance and cost efficiency. Quantifying this parameter enables systematic comparison across environments, deployments, and time periods, revealing optimization opportunities that improve both performance and cost-effectiveness.
Precise measurement of this value supports informed infrastructure decisions and helps engineering teams optimize system architecture for both performance and cost efficiency. Quantifying this parameter enables systematic comparison across environments, deployments, and time periods, revealing optimization opportunities that improve both performance and cost-effectiveness.
Manually computing availability from incident logs is tedious and error-prone. This calculator instantly converts raw downtime into availability percentages and compares against SLA targets, streamlining compliance reporting and incident retrospectives. Regular monitoring of this value helps DevOps teams detect anomalies early and maintain the system reliability and performance that users and business stakeholders expect.
Availability = ((Total Time − Downtime) / Total Time) × 100. For 720 hours with 30 minutes downtime: A = ((43200 − 30) / 43200) × 100 = 99.931%.
Result: 99.931% availability — SLA Met
In a 30-day month (720 hours = 43,200 minutes), 30 minutes of downtime yields 99.931% availability. Since the SLA target is 99.9%, the service meets its SLA commitment with 13.2 minutes of remaining budget.
Availability is the most widely used metric in service level agreements. It expresses the percentage of time a service is operational and accessible to users during a defined measurement period.
Monthly measurement is most common, but quarterly and annual windows are also used. Shorter windows are stricter because a single incident has a bigger proportional impact. Choose the period that balances accountability with operational flexibility.
Modern SLA frameworks go beyond simple up/down measurements. They incorporate performance thresholds (e.g., responses under 200ms), success rates (e.g., less than 0.1% errors), and user-facing metrics like Apdex scores for a more complete picture of service health.
Integrate availability calculations with your monitoring stack. Tools like Datadog, PagerDuty, and Grafana can automatically compute SLA metrics from incident data, reducing manual effort and improving accuracy.
Use synthetic monitoring or real-user monitoring (RUM) to detect outages automatically. Combine this with incident management records. Ensure your monitoring checks run frequently enough (every 30-60 seconds) to catch brief outages.
It depends on the service criticality. Internal tools typically target 99.5%, SaaS products aim for 99.9%, and critical infrastructure targets 99.99% or higher. Set targets based on user impact and engineering capacity.
Most cloud providers offer service credits (typically 10-30% of the monthly bill) when availability falls below the SLA target. Credits are usually applied to future invoices rather than refunds. Check your specific provider's SLA terms.
This depends on your SLA definition. Many SLAs exclude scheduled maintenance performed during designated windows. However, transparent reporting may include all downtime regardless of cause.
For active-active regions, calculate per-region availability and use the formula: Combined = 1 − (1 − A1)(1 − A2). For active-passive, the composite availability equals primary availability plus failover probability.
An SLI (Service Level Indicator) is a metric like latency or error rate. An SLO (Service Level Objective) is your internal target for that metric. An SLA (Service Level Agreement) is the contractual commitment with financial consequences for breaches.