The formula for calculating swap rates = Swap Rate x Lots (Volume) x Number of Nights = Swap (in base currency)
The first number that is required is the Swap rate itself. It can be either a positive or negative number that is based on interest rates. Swap rates are also different for long and short positions. So, if you placed a long position (buy) you will make the calculations with the Swap long rate and if you placed a short position (sell) you will use the Swap short rate.
Note: Swap rates vary from asset to asset and are measured on a standard size of 1 standard lot (100,000 base units for Forex pairs).
AUD/USD example:
Swap LONG is – 4.38
Swap SHORT is 0.14.
You opened a long position (BUY), so you will do the calculations with – 4.38.
Lots (Volume): In the case of AUD/USD, this number ranges from 0.01 and 40.
Triple Swap = Number of nights, in which the swap rates were applied.
So now we will carry out the calculation with our data.
The long swap of – 4.38 is multiplied by the 2 lots:
4.38 x 2 = -8.76 AUD
Or, if you held the position open for more than 1 day, multiply by the number of nights. In our case the position was open for 5 nights:
-8.76 x 5 = -43.8 AUD
This is the monetary value of the swap rate on your trade for those 5 nights. The number is positive and works in your favor.
The AUD/USD pair is charged in AUD. The amount would be then converted into the currency of your account.