You look up USD to VND, see one number, then get a noticeably worse rate at the airport counter. Nobody is necessarily cheating you — you're simply looking at two different kinds of rate. Knowing the difference helps you spot a fair deal.
What the mid-market rate is
Currencies trade between banks all day. At any moment there is a price at which dealers will buy a currency and a slightly higher price at which they will sell it. The mid-market rate is the midpoint between the two. It's what converters, news sites and most apps show you — a neutral reference rate.
Why your bank's rate is different
Banks, card networks and money changers don't trade at the midpoint with you:
- They buy your currency below the mid-market rate and sell above it. That gap, the spread, is their margin.
- Many add a fee or commission on top, or a percentage for card payments abroad.
- Airport and hotel counters usually have the widest spreads.
That's why the converter shows one rate and the bank board shows two (buy and sell), both different.
How to estimate the real cost
- Convert your amount at the mid-market rate.
- Compare it with what the bank or changer will actually give you.
- The difference, as a percentage, is the true cost of the exchange.
For example, if the reference says 100 units of your currency is worth X, and the counter offers 97% of X, you're paying about 3% — before any fixed fee.
Tips for travellers and expats
- Compare against the reference rate, not against another expensive counter.
- Decline "pay in your home currency" at foreign card terminals — the conversion rate offered is often poor.
- Exchange larger amounts less often if there's a fixed fee per transaction.
- Check the rate on the day. Rates move daily, and a quote from last week may be out of date.
How to use the currency converter
- Open the Currency Converter.
- Enter the amount and choose the currencies — popular ones such as VND, USD, EUR, GBP, JPY, KRW and SGD are listed first, with 160+ in total.
- Read the converted amount, the rate and when the rates were last updated, plus a quick table for common amounts.
- Tap ⇄ to swap the direction.
Rates are daily mid-market reference rates from ExchangeRate-API, with a backup source; they are not bank buy/sell rates. Your amounts stay in your browser.
Quick links for common pairs: USD to VND, VND to USD, EUR to VND, USD to EUR and GBP to USD.
FAQ
How often are rates updated? Once a day. Your browser keeps them for up to six hours so the page loads instantly on repeat visits.
Can I use these rates for accounting? Use them as a guide. For invoices and tax, follow the rate your bank, contract or tax authority specifies.
Does it work offline? Only with rates downloaded in the last six hours.
Try it now
Check today's reference rate with the free Currency Converter, then compare it with your bank's buy and sell rates before you exchange.