The Cross-Border Price Gap is the difference between what a product's Buy Box costs on one Amazon marketplace and what the same product's Buy Box costs on another, once the second price has been converted into the first's currency. Shown on the homepage as A2A Price Gap.
It is a gross price difference. It is the size of the window between two marketplaces, not the margin you would keep after selling through it.
What It Measures
For every product matched across a marketplace pair, the gap is a single percentage, measured against the source marketplace's Buy Box price.
Both sides of the comparison are Buy Box prices — the latest Buy Box we hold for the source listing and for the matched target listing. No other offer enters the calculation: not the lowest FBA offer, not the list price, not used offers.
A positive gap means the source marketplace is the more expensive side, so the target marketplace is where the product is cheaper. A negative gap means the reverse.
Alongside the per-product gaps, the result reports an average gap across the matched set.
Why It Matters for Resellers
A cross-border comparison is only worth running if the numbers coming back mean something specific:
- It sizes the window, not the trade. A gap tells you how far apart the two Buy Boxes are in the data we hold. Whether that distance survives fees, freight and duty is a separate calculation you still have to do.
- It ranks by signed gap, not by size of opportunity. The matched set comes back sorted from the largest positive gap down, so the biggest source-over-target windows are at the top. Reverse-direction gaps sort by the same rule, which puts the widest of them last among the priced matches: a −30% gap sits below a −5% one. Matches with no gap at all sort after every priced one, so if you are sourcing in that direction, skip the no-gap rows at the end and read up from the last priced match.
- It travels with its own caveats. Each match carries a confidence level and the result carries the exchange rate and the date that rate was set, so you can tell a solid reading from a thin one without leaving the answer.
How We Calculate It
- We match the product across the two marketplaces, by UPC/EAN where a code exists and by looking up the same ASIN on the other marketplace where one does not. See Cross-Marketplace Comparison for how matching works.
- We take the latest Buy Box price we hold on each side. Resolution is cache-first: a product looked up in the last 24 hours is served from cache rather than re-fetched from Keepa.
- We convert the target Buy Box price into the source marketplace's currency, normalising through USD and rounding to whole cents.
- We calculate the gap as (source Buy Box − converted target Buy Box) ÷ source Buy Box, expressed as a percentage and rounded to two decimal places.
- If either side has no Buy Box price, or the source price is zero, no gap is reported for that match. It is left empty rather than shown as zero, and the match sorts to the end of the list.
- We sort the matched set by gap, largest first, with the matches that have no gap last.
- We average the gap across the priced matches only, so matches with no Buy Box price on one side cannot drag the average toward zero.
How to Read the Results
| Reading | What It Means |
|---|---|
| Large positive gap | The source marketplace's Buy Box is well above the converted target Buy Box. The target marketplace is the cheaper side of the pair. |
| Small gap either way | The two marketplaces are priced close together once currency is accounted for. There is little room between them before costs. |
| Negative gap | The target marketplace's Buy Box is the higher of the two after conversion. The direction of any opportunity is reversed. |
| No gap reported | One of the two listings had no Buy Box price in the data used for the comparison. This is not a gap of zero — it is an unknown, and the match sits at the bottom of the list. |
The gap is a gross figure. Nothing has been deducted from it. Treat it as the starting number for a landed-cost calculation, never as the result of one.
Limitations & Caveats
- Gross, not net. The gap is a raw Buy Box price difference. Referral fees, FBA fulfilment, inbound freight, duty and the cost of the currency conversion itself are all still ahead of you. A 30% gap is not a 30% margin.
- The FX rate is a table bumped by hand. Rates are not fetched live. They are a fixed table, refreshed manually from the ECB daily reference rates, and intended for ballpark comparison rather than for pricing a transaction. Every result carries the exchange rate it used and the date that rate was set — check that date before acting on a gap, because the gap moves with the rate.
- The prices may be hours old. Resolution is cache-first, so a product looked up within the last 24 hours is compared at its cached price rather than a freshly fetched one, and Keepa's own data can lag Amazon. Confirm both prices on Amazon before acting on a gap.
- Match confidence varies, and the gap inherits it. Each match is scored high, medium or low. A high-confidence match is one where a single product on the target marketplace carried the same product code. Where several products share a code, title similarity decides which of them we match. Where there was no code at all, we look up the same ASIN on the target marketplace and match it if it exists — title similarity does not select that match, it only scores it, so a same-ASIN match with a dissimilar title still comes back, marked low. A low-confidence match's gap is a price difference between two products that may not be the same product.
Related Metrics
- Sell Price: what a product has actually been changing hands at, which is the number a gross gap has to survive.
- Price Position: where each side's comparison price sits in its own history, which tells you whether a gap reflects a durable difference or a temporary price move on one marketplace.