What is Uptime?

Uptime is probably the most important single metric you can use to measure the performance of your web host. It shows the time or percentage the service is up and operational. The counterpart of that is downtime. It shows the time or percentage the service was unavailable.

Availability is the same as uptime. It’s often measured by “Nines.” Let’s see how they translate to downtime for 30 days:

Calculations: Uptime Percentage to Downtime

NinesDowntime
99%Two Nines equals to 7 hours and 12 minutes downtime in 30 days
99.9%Three Nines equals to 43 minutes and 12 seconds downtime
99.99%Four Nines equals to 4 minutes 19 seconds downtime
99.999%Five Nines equals to 26 seconds downtime
99.9999%Six Nines equals to 3 seconds downtime

Check your uptime with the calculator below. You can either insert the duration of the downtime in the first row or the percentage of the uptime in the second row and hit Calculate. It will tell you the length and the proportion of the uptime and downtime.