# How price comparisons work

> What to Buy in Japan compares the same exact product where possible, estimates likely checkout prices, converts both headline numbers into the shopper's home currency, and shows a direct result.

- Japan prices and home-market prices retain their original source and capture date.
- FX is an informational daily midpoint estimate from [Exchange Rate API](https://www.exchangerate-api.com).
- The Japan headline uses a current direct duty-free receipt when one is available. Otherwise it uses a tourist tax-free estimate only when the seller route supports it and the tax-exclusive purchase is at least JP¥5,000; all other cases use the tax-included source price.
- A tax-exclusive US source price receives the 7.53% 2026 nationwide average combined sales tax. The actual rate varies by location.
- Shipping, card fees, warranty differences, duty, and import tax may change the final cost.
- Missing prices remain missing.

[Japan Tourism Agency tax-free guidance](https://www.mlit.go.jp/kankocho/tax-free/page01_000001_00028.html)

[US sales-tax source](https://taxfoundation.org/data/all/state/2026-sales-tax-rates-midyear/)