Phone Plan Cost Per GB Calculator
Divide your phone bill by the data you actually use to get a true cost per gigabyte — the fair way to compare plans.
How it works
Cost per line = plan cost ÷ lines · Cost per GB = cost per line ÷ GB used
Advertised plan prices hide the real value because they ignore how much data you actually use. Dividing the per-line cost by your monthly gigabytes gives a cost-per-GB that lets you compare a cheap capped plan against an expensive unlimited one on equal footing. Light users often pay a high effective rate on a big unlimited plan, while heavy users get more value from it — check your usage in your carrier app before deciding.
Worked example
A $60 plan on a single line where you use 10 GB works out to $60 ÷ 10 = $6.00 per GB. On a $120 four-line family plan that is $30 per line; a line using 15 GB pays $30 ÷ 15 = $2.00 per GB — far better value per gigabyte.
Frequently asked questions
How do I find my monthly data usage?
Your carrier’s app or account page shows data used per line, usually with a few months of history. Phone settings also track cellular data — on iPhone under Cellular and on Android under Network & internet — though you may need to reset the counter to align it with your billing cycle.
How do I compare an unlimited plan?
Enter your typical actual usage rather than “unlimited.” The cost per GB then reflects what you really get; if you only use 5 GB on a $70 unlimited plan that is $14 per GB, which may be worse value than a cheaper capped plan.
Should I include taxes and fees?
For the truest comparison, use the total you actually pay including taxes and fees, since these vary by carrier and region. Comparing pre-tax base prices still works if you apply it consistently to every plan.
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This calculator is for educational purposes. Double-check important results before acting on them.