You can find the swap rate for every instrument from the Market Watch on MT4 or MT5. Simply right-click on a symbol > then select Specification. A small window will pop up, and from there, you will see the swap information:
You will need the Swap long or Swap short rate, depending on your position, to calculate how much your swap is going to be.
Forex and Indices
Swap Rate x Lots (Volume) x Number of Nights = Swap (in base currency)
Suppose you are trading EURUSD, and you opened a short position (sell). Its swap short rate is 0.83, and you traded with 0.01 volume.
0.83 x 0.01 = 0.0083 << is the daily swap, which you’d need to multiply by the number of days you intend to keep the position open.
The swap will be in EUR if it is also your base currency. If it’s not, it’ll be converted to your base currency.
Commodities
Commodities are charged in USD, so they are converted to the account’s base currency (if it’s not USD).
For example, XAUUSD has a swap long rate of -2.26, and you placed an order of 2 lots:
-2.26 x 2 = -4.52
The swap would be -4.52 USD, which will then be converted to your account’s base currency.
Keep in mind that swaps are tripled on Wednesdays.
If a position is held overnight on a Wednesday (to Thursday), the normal swap rate is tripled. This is because spot forex trades have a 2-day settlement period; an FX trade closed on Monday settles on Wednesday, a trade closed on Tuesday settles on Thursday, etc. The markets aren’t open on weekends, but trades can still be held over this period. Charging triple swaps on a Wednesday effectively accounts for holding trades over the weekend.
Note: Swap rates of Oils, Indices, and Stock Shares are tripled every Friday.