There is only one real currency exchange rate. It's called the mid-market rate, the interbank rate or the spot rate (among other things).
The real rate is mid-point between buy and sell rates on the global currency markets. It’s the rate you find on Reuters, Xe, Google, finance.yahoo.com, etc and the only one that TransferWise uses.
We simply take in rate data from these sites and apply it when converting your money.
When you send from your USD bank account, this rate is locked in from the moment your transfer is set up on TransferWise.com.
You can check the exchange rate now by entering your currencies in the TransferWise calculator on our home page or on the first step of setting up your transfer. Or, try our currency converter tool here.