🖥️ Uptime Calculator
Convert an uptime percentage (SLA target) into the maximum allowed downtime per year, month, week, and day.
What uptime percentage means
Uptime is the fraction of time a system is available and working, usually expressed as a percentage such as 99.9% (“three nines”). The remaining fraction, (100 − uptime%), represents the maximum downtime allowed to still meet that target, commonly used in Service Level Agreements (SLAs) for hosting, cloud, and network services.
How this calculator works
Enter an uptime percentage, and the calculator converts the corresponding downtime fraction into actual time allowances: it multiplies the downtime fraction by the number of minutes in a year (using 365.25 days to account for leap years), then divides proportionally to get monthly, weekly, and daily allowances.
For example, 99.9% uptime allows roughly 8.77 hours of downtime per year, while 99.99% allows only about 52.6 minutes. This tool is for general planning purposes; actual SLA terms may define downtime windows or exclusions differently.