A site that is “down” is as good as not having a site at all – no visitors, no traffic, no revenue, nothing – zilch. Because of this, a very high uptime guarantee percentage should be your top, or at the very least, major criterion when choosing a host.


Not too long ago, the hosting industry was looking at 99%, then later 99.5%. These days, some people say you should never settle for anything less than 99.9% as 99.9% beginning to become the "industry standard"/the norm. As more and more hosts offering 99.9%, those offering less than that will surely lose out in the competition simply because uptime is so important to website owners.


But what does this percentage really mean ? It is actually a simple calculation :

the total number of minutes in a month x (100-uptime%)/100
= 30days x 24hours x 60min x (100-99.9)/100
= 43200 x (0.1)/100
= 43.2 minutes (max downtime).


So, if it is 99.9%, it means your website should not be down for more than a total of about 43.2 minutes in a month. Mind you, the total number of minutes in a month is about 43200 minutes or 720 hours. So, 0.1% of downtime is actually very minimal. Out of this much time, your host should only down your site for a max of 43.2 minutes – whether it is for maintenance work, reboot, troubleshooting (because some monkey shares the same server as you and ran some mass emailing program/malicious script that cause CPU usage to go red ? ), change of failed hardware etc.


This does not mean that your site will be down for 43 minutes every month. That figure is actually the longest or maximum down time. Some good hosts might actually give you 100% uptime for months in a row in reality – even though they state 99.9% for the guarantee that they give. These are hosts that take care of their CPU / RAM / executable file security etc – overall server environment properly.


Logically, the more domains/websites you plan to host in a single account, the higher percentage you should look for.


Also, do know how committed a host is in honouring their guarantee. Do they just mention it in their marketing channels, eg websites etc. Or do they really specify it clearly in their “terms of service” (ToS) ? What kind of compensation they plan to honour if they exceed the agreed upon max downtime ? Not all host are willing to compensate for exceeding the max downtime. Honest and responsible hosts will refund the hosting fees you paid for a particular month upon you reporting to them that they had exceeded the max downtime and they agree to it - and this is stated clearly in their ToS.


Finally, go for hosts that guarantee both server and network uptime. Do realise that most hosts just guarantee network uptime.


Hope this mini article helps.
Check out ryantoh.com/webhosting if you are looking for 99.9% uptime guarantee hosts.


JoeT (a webmaster & certified programmer)