What is the other meaning of 99.9% uptime?


Read through so many web hosting company. Some of the them stated 99.9% uptime guarantee, some of them mention 99% and 99.99% . As a customer, if we see 99.9% , the impression will definitely make most of us feel confident and positive thinking to the web hosting company.

Although 100% uptime is the ideal case, but in electronic and telecommunication world , we have to admit that nothing is 100% perfect and nothing can last forever. Any server or computer will definitely become old in one day , any switches , connectors or cables has a life span. Average of capacitor and transistor lifespan is between 5 years to 10 years.

Real Meaning

When a web hosting company is offering 99% or 99.9% , they are actually telling you that :

  • They have equipped the backup power supply for all the servers
  • The have sufficient IT man power for maintenance.
  • The maintenance and repairing job are managed efficiently.
  • If there is server down happen , the down time will be reasonable, it should not impact to your website.
  • They have all the website recovery plan in case the disk drive is broken.
  • All website will be mirrored . So all hardware maintenance will not impact customer .

Example of how the webhosting marketing their uptime ?

Now the question that we need to discuss here is.. Is the figure important ? Perhaps Yes, the higher percentage the webhosting dare to put, the more confident the web-hosting is going to guarantee.
For example, 

  • Bluehost do not mention any uptime guarantee in either website or the service agreement, they frankly tell you that the server uptime is dependent on a variety of issue and most issues are resolved in approximately 15 minutes and more than 15 mins for extreme issues.
  • InMotion ,Hostgator, GreenGeeks mention that they are offering 99.9% uptime guarantee
  • iPage,iPower,Lunarpages, FatCow do not specify in their website nor service agreement but iPage mentioned 99.9% uptime in the live chat support.
  • web.com hosting package states 99.99%uptime in their website.
  • Interserver ,hostrocket mention that they are offering 99.5% uptime guarantee
  • Webhostingpad indicate they are offering 99% uptime guarantee

Calculation of  downtime vs 99.9%  uptime

So, 99.9%, 99.99%, 99% and 99.5% are the common figures that we found at the webhosting company.  Do you think they will simply tell ? NO WAY!  Each of the giant hosting company are at least holding hundred thousand of customers. If the marketing team simply bluff just because of business, the supporting team will be in trouble. The figure is actually based on the statistic of all the servers uptime calculation. Lets look at the basic calculation

99.9% =  100% – (downtime )  / ( total duration) x 100%
if we take 1 year as the total duration , then
downtime = 0.001 x 365 days
                  = 0.001 x 365 days x 24 hours
                  = 8.76 hours = 8 hours 45 mins 36 seconds

Based on the calculations above, we can conclude that for those webhosting who guarantee 99.9% , the downtime should not be more than a 8 hours +  . What if we count the uptime by months. Ok, Lets do it again:

Now we take 1 month as the total duration.
downtime = 0.001 x 30 days x 24 hours
                   = 0.72 = 43 mins 12 seconds


uptime1It is a big difference if we count the uptime by months and by year, so now we know where is the marketing tricks. Before you sign up the package, please get to know it from your webhosting. It is for your record if anything happen. However, good hosting company is always trying their best to maintain the server uptime. We are showing this to you because if one day your website is down, don’t be too nervous , it is normal and the issue will be gone away soon at least not more than 44 mins per month counted. If it is really exceed 44 mins, make sure it will not down more than 9 hours per year counted . If the website is down more than the committed time or it is down too frequently ,  then you will have your right to submit the complaint or get prepared yourself to change the hosting.