Roaming Data Calculator
Compare roaming charges against a local SIM or eSIM for a trip.
About Roaming Data Calculator
Roaming is cheaper for very light use because a local SIM has a fixed cost, but the crossover comes quickly. At typical usage a two-week trip almost always favours a local plan. eSIMs removed the practical friction that used to justify paying roaming rates, which has moved the break-even point substantially in favour of local plans.
Formula
Roaming Data
Roaming cost = data volume × cost per GB + daily access fee × days
- daily access fee
- A flat charge some providers apply for each day roaming is used
- eSIM
- A downloadable local plan, avoiding the need to swap physical cards
Worked example
With the default values below, Roaming Data Calculator returns Cheaper Option of Local SIM or eSIM. Change any input above and every figure here is recalculated in your browser.
Inputs used
- Trip lengthminimum 1 days
- 14 days
- Daily data useminimum 0 MB
- 500 MB
- Roaming cost per GBminimum 0
- 8
- Daily roaming access feeminimum 0
- 0
- Local SIM or eSIM costminimum 0
- 18
Results
- Cheaper Option
- Local SIM or eSIM
- Total Data Needed
- 6.836 GB
- Roaming Total Cost
- $54.69
- Saving With a Local SIM
- $36.69
- Data at Which Roaming Becomes More Expensive
- 2.250 GB
Step by step
- 1Values used
- 2Roaming Data
- 3Cheaper Option= Local SIM or eSIM
- 4Total Data Needed= 6.836 GB
- 5Roaming Total Cost= 54.69
- 6Saving With a Local SIM= 36.69
- 7Data at Which Roaming Becomes More Expensive= 2.250 GB
Assumptions and limits
- The result is derived only from the 5 inputs listed above. Anything not among them is not part of the calculation.
- In particular, this calculator does not take inflation, tax or compounding frequency into account.
- Figures are rounded for display to 3 decimal places, so totals built from several rounded parts can differ slightly from the unrounded arithmetic.
How these calculators are built and tested is described on the Methodology page. If a figure looks wrong, please report it.
Frequently Asked Questions
How is Roaming Data calculated?
Roaming cost = data volume × cost per GB + daily access fee × days Roaming is cheaper for very light use because a local SIM has a fixed cost, but the crossover comes quickly. At typical usage a two-week trip almost always favours a local plan.
Why does Roaming Data matter?
eSIMs removed the practical friction that used to justify paying roaming rates, which has moved the break-even point substantially in favour of local plans.
What values do I need to enter?
This calculator takes 5 inputs: Trip length, Daily data use, Roaming cost per GB, Daily roaming access fee, Local SIM or eSIM cost. The pre-filled defaults are a realistic starting point — replace them with figures from your own environment for a result you can act on.