See also Data Transfer Usage Calculations, below,
for information on calculating or estimating your data transfer
needs. Don't want to read all this? Get right to the point by
What does "data transfer" mean?
In general, "data transfer" refers to any data transferred
into or out of a site. For example, graphics, text, movies, sound
files, programs that you or your visitors either download or upload
are all considered to be data. Every time a web surfer visits
your web pages, data is transferred from our server to their computer.
As you want a lot of people to "hit" your site, you
want a plenty of data to be transferred!
Does data transfer include my e-mail messages?
No. Although e-mail is a type of data transfer, ITS does not include
e-mail usage in calculating your hosting plan's data transfer
Are the files that I upload or download using either
FTP or HTTP subject to the data transfer limits?
Using FTP with your account and password is not part of data transfer
limits. However, anonymous FTP (a type of FTP access that lets
users login to another computer without using an account) is subject
to the data transfer limits. Also, transferring files from your
site with HTTP adds to your data transfer totals.
How can I monitor my data transfer usage?
You can use our on-line statistics monitoring to stay up-to-date
on your data transfer totals. To view the statistics go to your
Ensim Control Panel.
What are the odds that I could exceed my data transfer
The odds are small. In general, only 1 percent or less of our
customers tend to exceed the limits. Certain types of web sites,
however, may have very high data transfer rates. For example,
music sites and entertainment sites often consume large amounts
bandwidth. This can lead to high data transfer rates.
What happens if I exceed my data transfer limits?
As usage reflects the number of people visiting your site ("hits"),
exceeding the limit would actually be good for you. If you believe
that exceeding the limit was a "one time only" event,
you can simply pay for the overage, the additional data transfer
amount. However, if you think that your site could routinely exceed
your current plan's data transfer limits, you may want to consider
upgrading to a hosting plan that offers higher limits. For detailed
information on your options should your site exceed its monthly
data transfer limit, please upgrade to reseller
plan or contact email@example.com.
What happens if my business grows or if I think a lot
of people will be visiting my site?
Upgrade your plan. It is very important to let us know whether
you expect a large number of visitors to your site. For example,
if your site was featured on one of the popular morning television
shows, you could expect a dramatic increase in visitations. The
same would apply if you add a banner ad on a major site such as
Yahoo! or AOL. Likewise, popular sites that send flowers can expect
heavy usage on Mother's Day and Valentine's Day. To avoid any
interruptions of your service, please provide us with advanced
notice of any days on which you expect very high web site traffic.
We can then plan for that traffic accordingly.
Why are there data transfer limits at all?
Some web hosting companies say they do not have limits. We use
limits to protect those customers who use our shared hosting environments.
In such an environment, different web sites located on the same
server share system resources. If one site on the server uses
too many resources, access to the other sites that reside on the
server could be adversely effected. Portioning each site's resources
assures that, if one site uses too many resources, the other sites
in that shared environment will not experience any significant
reduction in performance.
Think of it this way: imagine that you are at a large conference
and, during a break, you want to make a quick phone call. However,
you misplaced your cell phone. So, you decide to call from the
lobby as it has several public phones. As this is a major conference,
many of the attendees also choose to make calls during the break.
What are your chances of getting an available phone? Well, if
unlimited use of the phones is allowed, your odds are not good.
However, if the conference coordinator asks each attendee to limit
his or her phone time to, say, no more than five minutes, your
odds of soon being able to find an available phone rises considerably.
So, in that "shared phone environment," placing time
limits on individual phone users allows more users to make calls.
This same logic applies to placing limits on computing resources
in a shared hosting environment. By placing limits on those shared
resources, no particular site can use so many resources that other
sites cannot function properly.
Theoretically, there are always limitations on the resources
that are available for use. If you need more resources for your
shared account, you can upgrade your account to one that has higher
resource limits. If you expect a consistent and very high number
of site visitors, you can elect to circumvent a shared environment
altogether by having your own dedicated server account. Such an
account provides you with all the system resources on a specific
I don't want to buy more than I need, but I don't want
to be hindered either. How do I calculate my expected data transfer
usage so that I can choose which plan is best for me?
Web sites differ greatly in terms of content, file size, number
of pages, number of visitors, and so on. To help you to estimate
your monthly data transfer usage, we provide some example calculations
in the following section called Data Transfer Usage Calculation.
In addition, you can always use the statistics options in Control
Panel to assist you with your estimates.
Data Transfer Usage Calculations
Before starting your data transfer calculations, you may need
a basic understanding of some typical file sizes and how they
relate to data transfer usage. The smaller the total size of a
web page, the quicker it downloads. Thus, many web pages are often
less than 30 KB in size. A typical graphic file (say, a .GIF file)
is about 20 KB to 30 KB in size. However, graphics on web pages
are usually smaller, often no more than 15 KB to 20 KB of total
graphics size per page. Sometimes web graphic files may be considerably
larger than 20 KB. However, for most web sites, using individual
graphics files larger than around 30 KB is not advised. Thus,
to speed the loading of your web pages, reducing the size of your
web page graphics is essential. You can reduce the size of your
graphic images by using the image optimizing features of many
popular graphics editing programs.
One megabyte (1 MB) is roughly 180,000 words of text -- about
the size of a typical novel. An easy way to calculate file size
is by using multiples of 1000. Calculations based on multiples
of 1000 are somewhat easier than those that use the binary method,
a method based on multiples of 1024. However, there are still
many calculations that are performed using binary units of measurement.
The easy way:
There are 1000 bytes per kilobyte (KB).
There are 1000 kilobytes per megabyte (MB) or 1,000,000 bytes.
There are 1000 megabytes per gigabyte (GB) or 1,000,000,000
bytes per gigabyte.
The binary way:
There are 1024 bytes per kilobyte.
There are 1024 kilobytes per megabyte or 1,048,576 bytes.
There are 1024 megabytes per gigabyte or 1,073,741,824 bytes
The equivalences shown above will prove helpful in understanding
the calculations in the following section, Example Calculations
Using the Binary Way.
Example Calculations Using the Binary Way
Estimating the Number of Files You Can Transfer Per Month
Typically, data usage is measured in bytes. The most common measures
are: kilobytes, megabytes, gigabytes, and terabytes. If you have
an account that allows up to 2 GB of data transfer per month and
your average file size is 10 KB, then you can move 209,715 files
per month. Here are the steps that we used to arrive at that answer:
Convert your average file size from kilobytes to bytes by multiplying
the average file size (10 KB) by 1024 (the byte equivalent of
10 * 1024 = 10,240 bytes
Determine the number of bytes in 2 GB by multiply the number
of bytes found in one gigabyte (1,073,741,824) by 2:
1,073,741,824 * 2 = 2,146,483,648 bytes
Finally, divide the number of bytes in 2 GB by the average file
size in bytes. This provides you with the number of 10 KB files
that your account can transfer per month:
2,147,483,648 / 10,240 = 209,715 files per month
As another example, if you have an account that allows up to
5 GB of data transfer per month and your average file size is
100 KB, then you can move 53,558 files per month. Here are the
steps that we used to arrive at that answer:
Convert your average file size from kilobytes to bytes by multiplying
the average file size (100 KB) by 1024 (the byte equivalent of
100 * 1024 = 100,240 bytes
Determine the number of bytes in 5 GB by multiplying the number
of bytes found in one gigabyte (1,073,741,824) by 5:
1,073,741,824 * 5 = 5,368,709,120 bytes
Finally, divide the number of bytes in 5 GB by the average file
size in bytes. This will provide you with the number of 100 KB
files that your account can transfer per month:
5,368,709,120 / 100,240 = 53,558 files per month
Estimating the Total Amount of Data Transferred Per Month
Sometimes, you may find it more useful to calculate the total
amount of data that is transferred per month instead of the number
of individual files transferred per month. For instance, if you
use a hosting plan that allows 5 GB of data transfer per month,
you may want to estimate how close your site will come to that
limit. If you are transferring from another hosting company to
ours, you probably already have a good estimate of your average
monthly total data transfer. In that case, you probably will not
need to perform the following calculation. However, if you are
starting a new site, you will need to take educated guesses regarding
the values that you need to enter into the equation mentioned
Realize that the following equation applies to sites that are
mostly informational. Those sites do not offer many downloadable
files. To estimate the total amount of data your site may transfer
per month, you would need to perform the following calculation:
# of visitors per month) * (Average web page size) * (Average
# of pages viewed per visit) = Data Transfer Total per Month
For example, let's say that you expect your site
to attract an average of 10,000 visitors per month. Further,
your average web page size is about 35 KB. You also expect
that visitors will view an average of 5 pages on your site
each time they visit. You calculation would be:
10,000 * 35 * 5 = 1,750,000 KB
So, your estimated monthly data transfer total
is 1,750,000 KB -- or about 1.75 MB. This is well below
your 5000MB (5GB) limit.
Using Our On-line Web Statistics to Better Estimate Your Data
If your site is very large or if it has numerous files for visitors
to download, you could still exceed your monthly data transfer
limit. Trying to estimate the monthly data transfer totals for
such a site is, at best, problematic. If your site provides large
or numerous files for download -- for example, MP3 files, Windows
wallpaper files, graphic files and so on -- you may first want
to contact our Sales team. Ask them for their expertise in recommending
a plan that fits both your budget and your site type (e-business,
music download, etc.). Then, using the Control Panel that we provide
with your account, you can monitor the total amount data transferred
during the first weeks of your site's operation. The Control Panel's
extensive statistical information allows you to determine if your
site will exceed its monthly data transfer limit. If it appears
that this will be the case, you can call us to upgrade your hosting
Measurement units: Even today, there is still a some confusion
about what kilobyte, megabyte, gigabyte, etc. actually mean. Traditionally,
the terms kilobyte, megabyte and gigabyte were used to express
the binary multiples of 1024, 1,048,576 and 1,073,741,824 bytes:
However, as people often think in decimal terms rather than in
binary terms, in December 1998, the International Electrotechnical
Commission (IEC: http://www.iec.ch) approved a new standard for
names and symbols for use in the fields of data processing and
data transmission. The standard was adopted in January 1999 by
the Institute of Electrical and Electronics Engineers (IEEE: http://www.ieee.org).
Thus, kilobyte, megabyte and gigabyte should now be used to express
the decimal multiples of 1000, 1,000,000 and 1,000,000,000 bytes.
A trio of new terms -- kibibyte, mebibyte and gibibyte -- are
now used to express the binary multiples of 1024, 1,048,576 and
Quote and acknowledgment to the authors, Fred Riley, University
of Hull and Graham Davies, Thames Valley University, of the following
back to top >>