Forex Swap Calculator
Estimate your overnight holding cost (or credit) using your broker's swap points.
What Is Forex Swap?
In forex trading, swap (also called rollover or overnight financing) is the interest adjustment applied when you keep a position open past your broker's daily cut-off time. Because every forex trade involves borrowing one currency and lending another, a small debit or credit is posted to your account each night.
Depending on the pair, direction (long or short), and current interest-rate environment, swap can either:
- Cost you money (negative swap), or
- Pay you money (positive swap).
How This Forex Swap Calculator Works
This calculator assumes your broker gives swap in points per lot per night. It then converts those points into money using point size and contract size.
Core formula
Daily swap per lot (quote currency) = Swap Points × Point Size × Contract Size
Total swap = Daily swap per lot × Lots × Effective Nights × Conversion Rate
Effective Nights = Nights Held + (2 × Triple-Swap Nights)
How to Use the Calculator (Step by Step)
- Select your currency pair and trade direction (long or short).
- Enter lot size and number of nights you plan to hold the trade.
- Set triple-swap nights (usually 1 for a full week hold in spot FX).
- Input your broker's swap long and swap short values.
- Confirm point size and contract size.
- Add conversion rate if quote currency differs from account currency.
- Click Calculate Swap.
Why Triple Swap Exists
Spot forex normally settles two business days after trade date (T+2). To account for weekend settlement timing, brokers charge or credit three days of swap on one rollover day each week. For many pairs, this is Wednesday night. For some CFDs and certain symbols, conventions can differ.
Factors That Change Swap Rates
1) Central bank interest rates
Rate differentials between the two currencies are the foundation of swap pricing.
2) Broker markup
Brokers often apply a spread/markup to financing, so real swap may differ from theoretical interest parity.
3) Market liquidity
During volatile periods or holidays, financing conditions can shift quickly.
4) Symbol type
FX majors, crosses, metals, and index CFDs can all have different rollover rules.
Practical Risk Management Tips
- Check swap values before entering swing trades.
- Include financing in your expected risk-reward calculation.
- Be extra careful near central bank announcements.
- Know your broker's server time and rollover cut-off time.
- Avoid surprise costs by monitoring Wednesday/weekly triple swaps.
Example Scenario
Suppose you are long 1.5 lots on EUR/USD with a swap long value of -4.0 points, point size of 0.0001, contract size of 100,000, held for 4 nights with one triple-swap event, and conversion rate = 1.
- Daily swap per lot = -4.0 × 0.0001 × 100,000 = -40
- Effective nights = 4 + (2 × 1) = 6
- Total = -40 × 1.5 × 6 = -360
Estimated swap cost is -360 in quote/account currency terms (depending on conversion assumption).
Final Thoughts
A forex swap calculator is essential for position traders and swing traders. Small overnight costs can compound over time, especially with larger lot sizes and long holding periods. By planning swap impact before entering a trade, you get clearer expectations, better budgeting, and fewer surprises in your P&L.
This tool is for educational estimation. Always confirm actual swap charges in your broker platform statement.