Downtime Minutes Calculator

Uptime percentage = ((total_minutes - downtime_minutes) / total_minutes) * 100. A 30-day month has 43,200 total minutes. If a service was down for 100 minutes, uptime = (43,200 - 100) / 43,200 * 100 = 99.77%. Compare this against your SLA target (often 99.9% = 43.2 minutes maximum per month) to determine if the SLA was breached.

SLA definitions vary. Most SLAs count downtime as periods when the service is not responding, returns errors, or performs below a defined latency threshold (e.g., response time above 5 seconds). Planned maintenance windows are typically excluded from SLA calculations if proper advance notice was given. Partial degradation (slow but functional) may count as partial downtime depending on SLA terms.

Cost of downtime = revenue_per_hour * downtime_hours + productivity_loss + recovery_cost + reputation/customer impact. For revenue-generating systems, revenue_per_hour = annual_revenue / 8,760. The Gartner benchmark is approximately $5,600 per minute for enterprise-grade outages, but this varies enormously by industry and system criticality.

SLA credits are financial remedies paid by a provider to a customer when the agreed uptime SLA is breached. Credits are typically expressed as a percentage of the monthly service fee. For example: below 99.9% but above 99.5% = 10% credit; below 99.5% = 25% credit; below 99% = 50% credit. Credits rarely cover the full business impact of an outage.

Add up all downtime incidents across the measurement period (usually one calendar month). Each incident's duration starts from first detection or customer report and ends when service is restored and confirmed. Post-incident reviews establish the precise timeline for SLA measurement purposes. Many organizations use automated monitoring tools to track cumulative downtime continuously.