Last updated: February 15, 2021
How Much Bandwidth Is Needed By Your Site? – Let’s Help You Do The Math
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One of the stickier challenges in finding a hosting solution is determining just how much server bandwidth your site will need. When you compare hosting plans, bandwidth (along with storage space) becomes much more important.
Unlike storage space, which can easily be controlled by deleting or offloading content as needed, bandwidth requires flexibility and subtle calculation. You don't want to pay for more than you need, but you also don't want to turn customers away or deal with the sometimes significant penalties for going over your allotted amount.
So how much bandwidth do you need? If you're willing to invest a little time and calculation to figure that out, you can balance both your bandwidth and your budget.
Bandwidth by the Numbers
If you're launching a new site, calculating your bandwidth is something of a shot in the dark. The best approach is to keep careful track of your site's activity for the first few months after it goes live so you can determine your actual monthly usage, and adjust your account accordingly.
For more established sites, calculating your estimated bandwidth is easy:
Estimate the average page size of your site, in kilobytes (KB). If you don't know, use Pingdom's Load Time test on a few pages and take the average.
Multiply this value by the monthly average number of visitors.
Multiply the result from step 2. by the average number of pageviews per visitor.
Keep in mind that your calculations must include every one of your sites hosted on the server. If (for example) you run twelve domains on the same account, take the time to add up the page sizes, visitors and pageviews across all domains. (If math isn't your strong suit, MarbleHost has a basic tool that can help. It even converts the final answer into GB, making it useful for determining how much bandwidth you should buy without having to carry the decimal.)
These simple calculations should give you an idea of how much bandwidth you can expect to use, but a little more math is required. Basing your usage allotment solely on these rough estimates won't give you the whole picture; you'll need to factor in real-world challenges and opportunities.
Leaving Room to Grow
Most sites don't use much bandwidth. If you don't host large media files or do a lot of streaming, you can usually get by with under 10 GB per month. For example, a modestly-popular blog with 1000 visitors per day, a 100 kb page size, and 2 page views per average visitor will only need about 8.5 GB of bandwidth per month.
Of course, these numbers are just an estimate, and they only apply to the here and now. Since you don't want to change plans or hosts every time your data shifts, you need to plan for the future and give yourself room—and reason—to grow.
Several factors can affect the bandwidth your site consumes.
Layout Changes: If you change your site's layout, you may increase the size of your page and use more bandwidth.
Traffic Growth: With any luck, traffic to your site will grow.
Room to Grow: As you add more pages, the number of pageviews typically increases as well, especially those from search engine spiders. And if you want to add more domains, it's usually far more convenient and affordable to do so with your existing account than by creating a new one.
Traffic Spikes: Unexpected traffic spikes, like those caused by social news sites, can cause bandwidth usage to double, or even triple, in a single month.
In many ways, choosing bandwidth is a lot like buying firewood where the general rule is to collect as much as you need, and then double or triple it. With bandwidth, you'll want to multiply your estimated need five- or even tenfold.
Though you may never use more than a fraction of your allotment, you'll be spared overage bills from even the heaviest traffic. Plus, since extra bandwidth is extremely affordable when built into a service plan (certainly cheaper than paying overages or the cost of having your site shut down during a peak time), it's well worth the price. By buying extra bandwidth (and lots of it), you're not just future-proofing your hosting, but also buying the peace of mind that comes from knowing you'll be prepared for whatever comes your way.