Forex Swap & Rollover Fees Explained
Hold a forex position overnight and you'll pay (or receive) a swap fee — here's how it's calculated, and why one day of the week hits differently.
Swap cost = swap rate per lot per night × lots × nights held, with one weekday (commonly Wednesday) charged 3× to account for the weekend when markets are closed.
Why triple swap exists
Forex markets are closed Saturday and Sunday, but positions held over the weekend still accrue two extra days of interest. Rather than charging swap on Saturday and Sunday directly, most brokers roll that cost into one weekday — commonly Wednesday — charged at 3× the normal rate.
Where the rate comes from
Swap rates are set by your broker based on the interest-rate differential between the two currencies in the pair, and differ for long vs short positions on the same pair. Always use the exact rate from your broker's contract specifications — it's never a value to estimate or guess.
Try Free Web Tools Mentioned in This Guide
Swap Calculator
Calculate overnight rollover cost for a held position, including triple-swap days.
Commission Calculator
Calculate broker commission, quoted per lot or per $1M notional, one-way or round-turn.
Position Size Calculator
Size your trade so a fixed % of your account is at risk — the #1 way traders blow accounts.
Frequently Asked Questions
Do all brokers use Wednesday for triple swap?↓
Most do, but not all — some use Friday instead. Check your broker's specifications and set the correct weekday when calculating.
Can swap be positive (a credit to me)?↓
Yes — depending on the interest-rate differential and your position direction, swap can be a credit rather than a cost. Carry-trade strategies specifically target positive swap.