Test the claim that dollars are always the better route

A dollar route is not automatically cheaper for THB, VND, or PHP. You need the won-to-dollar purchase quote, the destination’s dollar buying quote, charges on both trades, and note conditions. Without the second quote, the comparison is incomplete.

The THB figures below are fictional arithmetic examples, not live rates in Thailand, Vietnam, or the Philippines or a shop’s prices.

Use the same starting budget for both routes

Fix the budget at KRW 140,000. Assume a direct price of KRW 40.5 per baht, a dollar purchase price of KRW 1,400, and a destination quote of THB 35 per dollar. Initially set separate charges to zero.

Direct: 140,000 / 40.5 = about THB 3,456.79
Via dollars: 140,000 / 1,400 × 35 = THB 3,500
Arithmetic difference: about THB 43.21

This does not mean fractional banknotes can be collected. Apply both counters’ denomination, rounding, and remainder rules after the arithmetic comparison.

One omitted charge can reverse the result

If USD 2 out of the same USD 100 is charged for the second transaction, only USD 98 is converted. The receipt becomes 98 × 35 = THB 3,430, below the direct route’s arithmetic amount. This demonstrates a fee’s effect; it does not claim a real USD 2 fee exists.

Receipt via dollars =
((won budget − KRW charges) / dollar purchase price − USD charges)
× destination dollar-buying price − destination-currency charges

Example: ((140,000 − 0) / 1,400 − 2) × 35 − 0
= THB 3,430

Subtract a dollar-denominated charge before conversion into destination currency. Record whether each charge is in won, dollars, or destination currency before inserting it into the expression.

Check note conditions and quotation units

Ask which dollar denominations and note conditions the destination counter handles. With large figures such as Vietnamese dong prices, check digits and whether a quote is per one or per 100 units. Do not transfer a quick mental-conversion shortcut from another currency.

For note identification, use issuing-authority resources such as the Bank of Thailand security guide and Philippine central bank banknote guide. A design guide cannot establish the counter’s price or acceptance policy. Source links checked on 4 November 2026.

Finish the comparison for the actual itinerary

  1. Obtain the direct route’s final foreign receipt amount for the same won budget.
  2. Record times, currencies, fees, and note conditions for both dollar-route trades.
  3. Normalize units and fee currencies, then calculate the destination-currency receipt.
  4. Consider the extra trip, opening hours, and cash needed immediately after arrival.

Do not fill the second quote with a price from an old travel review. Marking an unknown item as unconfirmed makes the comparison’s limit visible.