99.9% UPTIME gives the following periods of potential downtime/unavailability:
Daily: 0h 1m 26.4s
Weekly: 0h 10m 4.8s
Monthly: 0h 43m 49.7s
Yearly: 8h 45m 57.0s
Many web hosting providers promise 99.9% of uptime.
But did you know that this is roughly 40 minutes of downtime per month?
In addition to that, according to our tests, almost half of the shared hosting providers fail to meet 99.9%.
Our uptime calculator helps you to see how much downtime are you actually facing. If you want to track your own site uptime/downtime - we recommend you to use Pingdom.
The SLA calculator assumes a requirement of continuous uptime (i.e. 24/7 all year long) with following additional approximations (as described in the source):