Forex Swap Calculator — Overnight Fee Estimator
Calculate the exact overnight swap fee (rollover cost) for any forex position. Enter your pair, lot size, trade direction, and number of nights to see your total swap cost — including triple swap Wednesday breakdown.
What is a Forex Swap?
A forex swap — also called a rollover fee, overnight fee, or financing charge — is the interest payment applied when a forex position is held open past the end of the trading day. In the forex market, the standard settlement period is T+2 (two business days). When you hold a position overnight, your broker effectively rolls the settlement forward by one day, which triggers an interest adjustment based on the interest rate differential between the two currencies in the pair.
Swap can work in your favour or against you depending on your trade direction and the interest rates of the currencies involved. If you are buying (going long on) a currency with a higher interest rate than the one you are selling, you may receive a positive swap credit. If the opposite is true, you will pay a swap debit.
How Forex Swap Works
When you open a forex position, you are simultaneously borrowing one currency to buy another. Each currency carries an interest rate set by its respective central bank. When the trading day ends at 5:00 PM New York time (22:00 UTC), your broker calculates the net interest difference between the currency you borrowed and the currency you hold.
Each currency has an interest rate set by its central bank. EUR has ECB rates, USD has Fed rates, JPY has BoJ rates. The difference drives the swap.
If you buy USD/JPY, you earn US interest rates and pay Japanese rates. The net difference — plus broker markup — is your swap charge or credit.
At 5:00 PM NY time, open positions are rolled forward. The swap is applied directly to your account balance — either as a debit or a credit.
How Forex Swap is Calculated
Brokers typically express swap rates in currency units per standard lot per night. The calculation follows this formula:
EUR/USD long swap rate = -5.20 per standard lot per night. You hold 2 lots for 3 nights (no Wednesday in the period).
Swap = -5.20 × 2 × 3 = -$31.20 total cost
Swap rates vary between brokers because each broker adds a markup to the interbank rate. Always use your broker's published swap schedule for precise calculations — the rates in this calculator are indicative defaults for reference only.
Triple Swap Wednesday Explained
On Wednesday nights, brokers apply three times the normal swap rate. This is not a penalty — it is a direct result of the T+2 forex settlement convention.
A position opened on Wednesday settles on Friday (T+2). When it is rolled over on Wednesday night, the new settlement date becomes Monday — skipping Saturday and Sunday. Since the weekend represents two additional days of interest accrual, the broker charges three days' worth of swap in one go: Wednesday + Saturday + Sunday.
For traders holding positions through Wednesday, the overnight cost is 3× the normal daily swap. This is a significant cost for large positions and should be factored into your weekly trading plan.
Long vs Short Swap — Key Differences
Every currency pair has two swap rates — one for long positions (buying the base currency) and one for short positions (selling the base currency). These rates are almost never symmetrical.
- Applied when you buy the base currency
- Negative if base currency has lower rates
- Positive if base currency has higher rates
- Example: Long EUR/USD is typically negative (USD rates > EUR rates recently)
- Applied when you sell the base currency
- Negative if quote currency has lower rates
- Can be positive on select pairs
- Both long and short can be negative simultaneously (broker markup effect)
Swap-Free (Islamic) Accounts
Swap-free accounts — often called Islamic accounts — do not charge or pay overnight swap fees. They are designed for traders whose religious beliefs prohibit the payment or receipt of interest (riba) under Islamic finance principles.
Instead of charging swap directly, some brokers substitute a flat administrative fee after a position has been held for a specified number of nights (typically 3–7 days). Others offer genuinely fee-free overnight holding for qualifying instruments.
Why Overnight Fees Matter for Traders
For day traders who close all positions before the rollover cutoff, swap is irrelevant. But for swing traders, position traders, and carry traders, overnight fees are a material cost that directly impacts profitability.
Holding positions for 3–10 days means 3–10 swap charges. On a 5-lot position with a $5/lot/night swap, that's $25–$75 in overnight costs before any P&L is considered.
Carry traders specifically target pairs with large positive swap differentials, earning daily interest income. Correct swap calculation is central to carry trade strategy profitability.
Many prop firm evaluation accounts include swap costs. Ignoring swap on a 5-day hold can push a borderline-passing account into a drawdown violation.
Frequently Asked Questions
The Forex Swap Calculator is provided for informational and educational purposes only. Swap rates shown are indicative defaults — actual rates vary significantly between brokers, account types, and market conditions. Always verify swap rates directly with your broker before making trading decisions. This tool does not constitute financial, investment, or trading advice.