Website uptime is the percentage of time that a website is up and available.

Example website uptime calculation:

Let’s say your website,, was up and available all month, except for a 30 minute period where it was inaccessible. We would say had 30 minutes of downtime.

To calculate your website uptime percentage for the month:

  • 43,800 minutes in a month
  • 30 minutes of downtime
  • 30/43,800 = 0.0006849315

That’s 0.06% downtime for the month, which means that: has a website uptime of 99.94%.

What is a good website uptime goal?

Many people consider 99.9% the minimum acceptable uptime. 99.99% uptime is a good goal to aim for–that requires less than 10 minutes of downtime per month.