Free calculator · Mobile
Mobile data calculator
Tell us what you do away from Wi-Fi in a typical week and see the monthly data you need, then the cheapest SIM-only plans for it.
Away from Wi-Fi, in a typical week:
You need about
24GB a month
That is your video, calls and music plus a quarter on top for maps, social apps and browsing. Look at SIM-only plans 10 to 49GB.
How the calculator works
The calculator estimates your monthly data from what you use away from Wi-Fi. It is free, needs no sign-up and runs in your browser, so nothing you type reaches us.
It works in three steps. First, it adds up your use away from Wi-Fi. Second, it turns a typical week into a month. Third, it adds a quarter on top for maps, social apps and browsing.
Video uses far more data than music. Netflix says HD video uses up to 3 GB an hour, while Spotify on its Very high setting uses well under 0.2 GB.
Not sure of your habits? Check last month in your phone settings, then compare SIM-only deals.
Use less data without trying
Three simple habits cut mobile data use without much effort. Start by downloading films, shows and music on Wi-Fi before you leave home. Then turn on the data saver setting on your phone. Next, check your phone settings to see how much mobile data you used last month.
Once you know that number, pick the right tier. Our SIM-only deals table has tabs for under 10GB, 10 to 49GB, 50GB and more, and unlimited. Choose the tab that matches your use, then compare the deals in it.