What is the difference between average daily sessions vs average daily hits for website traffic?

Question

I am referring a link

https://www.eurovps.com/blog/how-much-ram-cpu-storage-iops-vps-needs/

to come up with a rough estimate on sizing.

For bandwidth consumption, the example used there is

Page Size ± = 1.8MB
Average Page views per Session: 5.97
Average Sessions per Day: 1,500
Bandwidth Consumption per Day: 16,119MB (16GB)
Bandwidth Consumption per Month: 16GB x 30 Days = 480GB

I was trying to map this formula based on the factual information I have for a website whose hardware sizing I am trying to arrive at and below is the data for it

Based on my assessment,

The page size for my website can be 1.8 MB on an average.

The part where I need some help is that for the formula to arrive at bandwidth, can I use number of hits per day in place of average sessions per day?

If I do, my equation comes to 1.83162161 = 875669.4 MB i.e. 875.6 GB

Answer 1

While that link is quite useful, I don't think it is helpful to you.

A hit on a website is viewing a single page while a session would be all the hits on that site from a single browser in a given period (loosely, when someone visits the site and looks around other pages, that whole interaction is a session. Because the web is historically stateless, it is difficult to tell when a session starts and ends, so an approximation has been made).

Based on your assumptions, your maths looks wrong - if there are 5,027,000 page views per month * 1.8 megabyte per view, that comes to 9,048,600 = 8.63 terabytes (9048600 / 1024 / 1024)

Note that the result makes a lot of assumptions that are likely incorrect - particularly that a page is 1.8 megabytes and that the heavy parts of it (ie the images) are not cached. While its plausible, it does not seem likely for a site with that many hits.

Answer 2

What does the 1.8MB consist of? Usually the first page view uses much more bandwidth, as any additional hits has much of the static content (css, js, images) cached. So visits*page size:

5270000*1.8 = 9486000MB (9.486TB) per month

/30 = 316.2 GB per day

The additional views per visitor will add some traffic, but at the same time repeated visitors with some static content already cached will likely use less, so without any additional info I would just use 316 per day (or maybe 400-500 GB to be on the plus side) as a rough estimate.

But it really depends on how much of the 1.8MB is static, cachable content, and how many repeated visitors you get. Also make sure it's actually loaded from your domain, if some of the content comes from 3rd party servers (for example ads), you can subtract it.