Dual SIM Data Plan Stacking Calculator
Carriers push a bigger single plan, but nobody runs the numbers on stacking two smaller eSIM plans instead. Enter both options below and see which one actually costs less per gigabyte. Nothing uploaded.
Comparison
| Option | Total cost | Total data | Cost / GB |
|---|---|---|---|
| Stacked (A + B) | - | - | - |
| Single plan (C) | - | - | - |
Verdict
Learn more: when stacking two SIMs saves money
Cost per GB decides it
The calculator adds the prices of plans A and B, adds their data, and divides total cost by total data. It does the same for the single plan C, then compares the two cost-per-GB figures.
With the default numbers, two plans at $15 for 10 GB stack to $30 for 20 GB, or $1.500 per GB. A single plan at $35 for 20 GB costs $1.750 per GB, so stacking is cheaper by $0.250 per GB. The percentage shown is that gap divided by the higher of the two figures, which is 14.3% here.
When one bigger plan wins
The single plan wins whenever its cost per GB is lower. Two $20 plans with 15 GB each cost $1.333 per GB. A single $50 plan with 50 GB costs $1.000 per GB, which is 25% cheaper, even though the stacked option is $10 less in total.
Higher data tiers are often cheaper per gigabyte, so the comparison can flip as you change the size of plan C. Try a few sizes to see where it flips.
What the math leaves out
The calculator compares price and data only. It does not account for overage charges, taxes, promotions that expire or the quality of coverage. Data on each plan also stays on that SIM, so the stacked total only helps if you will really use both allowances.
If you are stacking for redundancy, check which network each plan runs on. Some prepaid brands share the same underlying network as others, in which case two plans may fail together.
FAQ
Does the calculator need a dual-SIM phone?
No. The cost math is identical whether both plans sit in one dual-SIM or eSIM phone or in two separate devices. The calculator only uses price and data for each plan.
What does the percentage in the verdict mean?
It is the cost-per-GB gap divided by the higher of the two cost-per-GB figures. In the default example the gap is $0.250 and the higher figure is $1.750, so the cheaper option is 14.3% less.
Is stacking worth it for the data alone?
Only when the stacked cost per GB is lower than the single plan's. Many people stack for other reasons, such as a second phone number or a backup network, and the calculator shows what that choice costs per GB.