How much mobile data do you need?

(Credit: Nokia)

We've all heard the horror stories of people being charged thousands of dollars in a single month after using their mobile phone data without knowing how much it costs in advance. The rise in popularity of excellent web browsing handsets has all but replaced the question, "Do I need mobile data?", with the more frustrating question...

"How much data do I need?"

Trying to add up your potential data usage may seem like a nightmare, so many people fork over large wads of cash each month to ensure they don't feel the sting of bill shock. But with a little common sense and mathematics it isn't too hard to figure out the cheapest plan suited to your needs to stay connected.

Firstly, you need to break down the main data sinks on your new phone — web pages, email, streaming video and downloads — and consider how much of each you're likely to use.

• A standard web page is likely to download between 200-500 kilobits (Kb) of data
• Text-only emails are about 10Kb
• Watching a YouTube clip is about 1MB (megabyte) for every two minutes of video you watch
• Downloading a song from iTunes is roughly 5MB, an album is likely to be more than 50MB

The greatest variable in this equation is downloads, like application downloads from Apple's App Store. A quick browse over the top apps shows regular apps averaging at about 5MB per download, though some of the popular games are much higher, like Doom Resurrection chewing up 80MB of data.

If all of this maths seems overwhelming, Vodafone Australia has a fantastic Data Calculator tool on its web page with drag-able usage markers allowing you to play around with a monthly allowance. Our only issue with this tool is that Vodafone calculates applications as tiny Java apps, like Google Maps, and suggests the average download for an app is about 200 kilobytes (KB). People shopping around on the Apple App Store or the Android Market would be wise to follow our 5MB per app average.

Vodafone Data Calculator — 200MB goes a long way on the mobile web (Screenshot CNET Australia)

Other cost-savers — Wi-Fi and carrier portals

So you think you have a pretty good handle on your web usage, and you think you know how much data this amounts to? Don't forget there are other avenues for using data that could reduce the amount of data you need to pay for each month. If you've set up a Wi-Fi network at home, or if there's one in the office you have access to, don't forget to punch these details into your Wi-Fi-enabled smartphone and piggyback on these accounts as often as possible, especially when downloading apps and music.

Wi-Fi is also an option when you're out and about. McDonald's restaurants offer free Wi-Fi for customers, as do Gloria Jeans Cafes, as well as many independent retail outlets. If you're sitting at the bus stop and you're thinking about reading the latest phone reviews on CNET (and who could blame you!) scan for open Wi-Fi points before using 3G. We don't recommend you connect to private connections left open by thoughtless owners, but it's always worth a look in case you're in range of a Maccas.

Also, all of the major Australian phone carriers include access to their secure web portals as part of your monthly contract; Telstra has BigPond, 3 Mobile has Planet 3, Optus has Optus Zoo, and Vodafone has Vodafone Live.

Check out what content they have available and see if it overlaps with any of your daily use. Most of these sites have regularly updated news coverage, sports and weather, and using this would save data on a daily visit to the Sydney Morning Herald website. Likewise, you could cut a huge chunk of data use out of the equation by watching carrier-run mobile TV services rather than YouTube, though many of these attract a separate subscription charge before you can watch them.

How much mobile data do you use each month? How does this compare to the amount of data you pay for? Let us know your thoughts in the forums.