Mobile Data Plan Calculator
What a mobile plan costs at your real usage — the base price plus any overage — the effective price per gigabyte, and the usage at which stepping up to a bigger plan becomes cheaper than paying for extra data.
A plan includes a data allowance; use more and you pay per extra gigabyte, usually at a steep rate.
How the mobile data plan calculator works
A plan includes a data allowance; use more and you pay per extra gigabyte, usually at a steep rate. So a plan that looks cheap can cost more than the next one up. The break-even is the usage where the overage equals the price difference: below it, stay; above it, upgrade. The daily-usage row translates your habits into a monthly figure.
Formula: cost = price + max(0, usage − included) × overage; upgrade when usage > included + (bigger price − price) / overage
Worked examples
| Inputs | Cost this month | Note |
|---|---|---|
| 28 GB on a 20 GB plan | 115 | upgrade |
| Within the allowance | 35 | stay |
| From daily usage | 35 | 18 GB a month |
FAQFrequently asked questions
How much mobile data do I use?
Check the phone's data settings for the last month, or estimate: an hour of HD video is about 1.5 GB, of music 100 MB, of maps 5 MB. Most people use 5 to 20 GB a month.
Why is overage so expensive?
Because it is priced to push you onto a bigger plan. Ten per gigabyte against a plan that includes 30 for the price of 20 extra — the break-even is only a gigabyte or two over.
Should I just take the biggest plan?
Not unless you use it: unused data is money spent. The break-even row says where the upgrade actually pays.
What about data banking or rollover?
Rollover lets unused data carry into the next month, which effectively raises the allowance for uneven users. This page treats each month on its own.
Does Wi-Fi usage count?
No — only mobile network data. Connecting to Wi-Fi at home and work is the cheapest way to shrink the plan you need.
Where these figures come from
- International Energy Agency — Energy Efficiency — appliance consumption and standby power context
- US Energy Information Administration — the federal energy statistics agency
Last checked: September 2026. Appliance power figures are typical ratings; check the label on your own equipment, which is authoritative for it.