Using OANDA Rates® for currency conversion

Please note, this FAQ applies only to OANDA's FX Data Services, which provides exchange rate subscriptions and other FX services for businesses. OANDA is a rate provider only. OANDA does not convert currencies or provide a remittance service.

Frequently asked questions


How are OANDA Rates calculated?

The exchange rates provided by our Currency Converter and other tools are averages for the global foreign exchange market gathered from frequently updated sources, including our OANDA fxTrade currency trading platform, leading market data vendors, and contributing financial institutions. The data is filtered and stored in a proprietary data repository.

We do not take market closing prices as the "average" price. Instead we take the average from all our collected data over a 24-hour period, reflecting the fact that the foreign exchange market never really "closes" globally. However, the volume of market activity is lower on weekends and holidays, so the number of prices varies from day to day. Our rates are rounded up to five significant digits, with a few exceptions.


How accurate are OANDA Rates?

OANDA Rates are trusted by top accounting firms, international corporate and financial institutions and individuals, and are a recommended resource for tax authorities worldwide.

For major currency pairs, our rates are based on tens of thousands of different price points, collected every few seconds, 24 hours a day, 365 days a year. We collect these rates from live data suppliers, filter them to remove false prices and validate the data, and use the filtered data to compute interbank market rates.

Note: you may see this message in the Currency Converter's details section: "Estimated price based on daily US dollar rates." This message is displayed for currency pairs where relatively little data is available, and means that the exchange rate for the converted currencies was computed from cross rates with the US dollar.


How often are OANDA Rates updated?

The period of time over which the average bid/ask currency price is taken depends on the data available for the particular currency. When possible, we take the average of prices over the last 24 hours and use these averages to update the rate every day at 00:00 UTC (Coordinated Universal Time).

Prices for the currencies of some emerging market countries may be published once per day or even less, resulting in only a few price points each week for these currencies.


Why can't I get interbank rates from a bank?

The prices quoted by the Currency Converter are based on interbank market rates and generally reflect the exchange rates for transactions of USD1 million or more. These are the "official" rates quoted in the media, such as ‘The Wall Street Journal.’ Retail spreads (the difference between the Bid and Ask prices) for smaller amounts are not reflected in these interbank prices since they vary among payment systems, countries and banks.

If you go to a bank in your home country, you usually have to pay more of your home currency to get foreign currency than you will receive of your home currency, if you return the foreign currency. This results in the two exchange rates shown in the margin result.

Because these retail rates vary so much in every place, we cannot advise you where to go at any given moment to change currencies. You can usually find this information from your local bank, travel guides, or from people who have visited the place you are heading for.


How do I choose the rate that applies to me?

Interbank rates (+/- 0%), with a margin close to zero, are the "official" rates quoted in media such as ‘The Wall Street Journal’. They typically reflect the market rates for large transactions of USD1 million or more when banks trade between themselves or with very large clients.


For the smaller amounts exchanged in a retail setting, banks, credit cards and exchange agencies charge commissions to convert currencies. These retail rates add commissions of 1 to 10 percent or more. For example:

  • ATMs typically add 2% (and then add service charges in many parts of the world)
  • Credit cards typically add 3% (for the major currencies; more for other currencies)
  • Foreign exchange kiosks and banks often add 5% when you convert hard cash (for the major currencies; more for other currencies).

Retail rates vary widely between payment systems, countries and banks, so we encourage you to enquire about the rates your financial institution is actually charging you.

To add a commission to your conversion, you can use the Interbank +/- pull-down on any of our applications. Either choose the commission from our list of typical charges, or type in a value if you know the rate you will be paying:

When you convert currency, you sell one currency to buy another. Your financial institution charges you a different rate if you are selling a currency (the Bid or Sell rate) or buying a currency (the Ask or Buy rate).

FXDS - FAQs - Bid or Sell Rate

You can see these two types of rates in the details section of the Currency Converter.

The Bid (or Sell) rate is the lower amount. You will receive fewer euros when selling your dollars (this is the number you see in the right field of the converter).

The Ask (or Buy) rate is the higher amount. It will cost you more dollars when buying euros.

Many currency information sites provide the midpoint rate, which is the average of the Bid and Ask rates for a currency pair. At OANDA, we default to the Bid price for our applications, as it more accurately mimics the rate that you would be charged if you were exchanging money. We do provide midpoint rates as a point of reference in our Historical Exchange Rates tool.

FAQ Help Portal

Get answers to frequently asked questions about our Exchange Rates API, Historical Currency Converter, FX payments and more.

Currency services FAQs

Learn about our range of services, including chargeable services such as the multi-seat historical exchange rates API and more.

Questions about FX payments?

Get information on how our FX payments work, which currencies are supported, transaction amounts, payments and more.