Cost of downtime calculator
What does one hour of outage actually cost your business? Revenue loss plus idle payroll, turned into the number that wins budget meetings, and a table showing what each availability tier from 99% to five nines costs you per year.
Cost per hour of downtime
What each availability tier costs per year
| Availability | Downtime / year | Annual cost |
|---|
How it's calculated
Hourly cost has two parts. Revenue loss is annual revenue × dependent share / operating hours: the money that simply does not come in while the system is down. Productivity loss is employees × loaded hourly cost × productivity lost: payroll you keep paying while people wait. The yearly figures multiply that hourly cost by the downtime each availability tier implies over your operating window: 99.9% of 8,760 hours means 8.8 hours down per year, 99% means 87.6 hours, and five nines means 5 minutes.
The savings line under the table is the argument this tool exists for: the yearly cost difference between your current tier and the next one is the budget ceiling for whatever gets you there, whether that is a second site, better backup infrastructure, redundant links or an on-call rotation. If the improvement costs less than that difference per year, the business case writes itself; if it costs more, now you know that too.
What the model deliberately leaves out, and why the real number is usually higher: reputational damage and customer churn, contractual SLA penalties, data loss (this prices unavailability, not lost transactions, which have their own and often larger cost), recovery labor and overtime, and the fact that outages do not respect averages. An hour down during your peak sales window costs a multiple of the average hour, so if your revenue is seasonal or spiky, run the numbers with peak-hour revenue too. Treat the output as the conservative floor of what downtime costs you.