You probably don’t need this exchange calculator unless your math skills are exceptionally bad. To relativize prices, use these three methods.
For currencies whose value is more or less than 50% against the dollar, it is useful to find a rounded reference point. For example, the Mexican peso is between 18 and 22 per dollar. When rounding to 20, quick swap calculations can be performed by moving the decimal place and dividing by two; 800 pesos becomes 40 dollars.
For currencies up to 50% above the dollar, consider the difference as a tip. If the Euro is trading at 1.05 to the US dollar, just add a 5% “tip” to the price. For currencies up to 50% below the dollar, use the discount method. If the Canadian dollar is trading at 75 cents on the dollar, discount amounts by 25%.
The third method is for currencies with an exchange that is not quickly “computable”, such as the Thai baht, which at press time trades for around three cents in the United States. Simply check the trade amount for US$10 and adjust as needed. $10 USD equals 343 baht today, so round up to around 350 and use that as a reference. The important thing to remember is that trades vary based on who makes the trade, what card is used, and other factors, so keep an eye out for relative trades, but don’t worry about mental math until the end. last decimal – focus on enjoying your travels instead.