What is an SLA uptime percentage?

An SLA (Service Level Agreement) uptime percentage defines the minimum amount of time a service promises to be operational. For example, 99.9% uptime (three nines) allows approximately 8 hours and 46 minutes of downtime per year.

How much downtime does 99.99% uptime allow?

99.99% uptime (four nines) allows approximately 52 minutes and 36 seconds of downtime per year, or about 4 minutes and 23 seconds per month.

Is this SLA calculator free?

Yes, the ServiceAlert.ai SLA Calculator is completely free with no signup required.

SLA Uptime Calculator

Convert SLA uptime percentages to allowed downtime. Essential for DevOps, SRE, and infrastructure teams.

SLA Uptime Percentage

Allowed Downtime

Per Day

1m 26s

Per Week

10m 5s

Per Month (30d)

43m 12s

Per Year

8h 45m 36s

Common SLA Levels

SLA Level	Nickname	Downtime / Year	Downtime / Month
99%	Two nines	3d 15h 36m	7h 18m
99.5%	Two and a half nines	1d 19h 48m	3h 39m
99.9%	Three nines	8h 45m 36s	43m 12s
99.95%	Three and a half nines	4h 22m 48s	21m 36s
99.99%	Four nines	52m 33.6s	4m 19s
99.999%	Five nines	5m 15.4s	25.9s

What is an SLA Uptime Calculator?

A Service Level Agreement (SLA) defines the expected uptime for a service. For example, a "three nines" (99.9%) SLA means the service can be down for no more than 8 hours and 45 minutes per year. This calculator converts any SLA percentage into exact allowed downtime across different time periods.

Why Does SLA Matter?

Understanding your SLA targets helps you plan infrastructure, set up monitoring, and negotiate vendor contracts. The difference between 99.9% and 99.99% uptime is nearly 8 hours of additional required availability per year. ServiceAlert.ai monitors 695+ cloud services in real time to help you track whether your vendors meet their SLA commitments.

View current incidents across all monitored services, or set up alerts to get notified when services you depend on go down.