Enter how much mobile data you used, not Wi-Fi. One month is fine. Two or three months gives a better answer.
Most data calculators ask you to guess how many hours of video you watch, how many songs you stream and how many websites you visit. Few people know those numbers, and small guesses add up to big differences.
Your phone or your provider may already keep count. If you can find a few months of reliable figures, they show what you actually use, including the busy months, and that's a better starting point than a national average or a guess.
The aim is to find how much mobile data you used in one or more recent months or billing periods. Depending on your phone and your provider, that may be easy to find, hard to find or not shown at all. Before you enter a figure, check which period it covers.
Many providers show how much data you've used in your current billing period, and the ACCC notes these figures can take a little while to update. Some also show past billing periods or past bills, and some don't. If yours shows how much data you used in recent billing periods, those are good figures to use.
Current Period doesn't mean this month or your billing period. It covers everything since the Last Reset date, so if the statistics haven't been reset for a long time it can be months or even years of use. In that case, don't enter it as one month's usage. Apple suggests contacting your provider for the most accurate usage figure. If Connectivity Assist is turned on, your iPhone can use mobile data alongside Wi-Fi when the Wi-Fi is poor, and that counts too.
Menus vary by brand and software version. Two common examples:
Your phone's figure is an estimate. Google and Samsung both note it may not match what your provider measures, so if they differ, go with your provider's figures. Android phones can also warn you, or turn mobile data off, when you reach a level you choose.
Can't find a useful monthly figure? That's okay. Some phones and mobile accounts don't show a simple history of how much data you used each month. If you're not sure what period a figure covers, it's better to leave it out than to enter it. If you can find one reliable month, that's enough to get started.
If your phone shows usage in MB, 1,000MB is about 1GB.
This is Money Detective's own approach, not an official or industry standard. It's designed to give you enough room without pushing you towards data you're unlikely to use.
Say you used 18GB, 23GB and 16GB. The average is 19GB, so a 20GB plan sounds right. But you've already had a 23GB month, which would have run over. Starting from 23GB and adding about 10% gives 25.3GB, which rounds up to at least 30GB.
If one month was much higher than the other two, the calculator asks whether it was a normal month for you. A holiday, a stretch without home internet or a lot of travel can push one month up, and you can choose whether to include it.
The ACCC's internet activity report for the December 2024 quarter found that:
Both were the highest figures in the series. Post-paid use was 56% higher than in December 2021, so it's worth checking your own use every so often.
These are averages across millions of services. Some people use a lot less and some use a lot more, so treat them as context, not a guide to what you should buy.
It's enough if your busiest recent month was about 18GB or less. That leaves a little room on top of what you've actually used. If you've had a month above that, a 20GB plan could run out, and a 25GB or 30GB plan may suit you better. Enter your own months above to check.
For most people it's plenty, but it depends on your own use. If your busiest recent month was about 45GB or less, 50GB leaves some room. If your busiest month was well under that, you may be paying for data you don't use, so it's worth checking whether a smaller allowance costs less.
No. Your allowance only covers data used over the mobile network. Anything you do on home or work Wi-Fi doesn't count, which is why your Wi-Fi habits make such a big difference to how much mobile data you need.
It depends on the plan. The ACCC says some plans automatically top up your data, which can be expensive, while others slow your speed once the allowance runs out. Providers must send usage alerts at 50%, 85% and 100% of your allowance, but they have up to 48 hours to send them, so check what your plan does before you sign up.
Only if you need it. Bigger allowances usually cost more, and if your busiest month is well below a plan's allowance you're paying for data you don't use. eSafety's Be Connected guide points out that it's usually easier to move up to a bigger plan than to move down to a smaller one.
No. The suggestion is a practical starting point based on the months you entered. If your habits change, a month could still run higher, so keep an eye on your usage alerts.
A 28-day plan's data covers 28 days, while a calendar month has 28 to 31. If your figures are monthly, a month's use can be a little more than one 28-day allowance. Check your figures against your plan's renewal period, and lean towards a little more room if you're close to the limit.
The data suggestion is based only on the figures you enter, using Money Detective's own rule of thumb. It doesn't guarantee you won't go over a plan's allowance. Nothing you enter is sent to Money Detective or any provider.
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