Swap Cost Calculator

What it is

A swap (also called rollover) is the interest you pay or receive for holding a forex position overnight. It exists because forex trades involve borrowing one currency to buy another — and borrowed money has an interest rate. If you buy a currency with a higher interest rate than the one you're selling, you may earn a small swap credit. If the rate goes the other way, you pay. This calculator turns your broker's published swap rate into a real dollar cost over your holding period.

When to use it

Before entering any swing trade or position trade you plan to hold for multiple days or weeks. When comparing brokers — swap rates vary significantly and can turn a profitable strategy into a losing one over time. When calculating the true cost of a carry trade, where the whole point is earning the interest rate differential. And when reviewing why your broker's P&L doesn't match your pip-based calculation — swap is usually the explanation.

The formula

Swap cost per night = Swap rate (in points) × Pip value × Lot size

Total swap cost = Swap per night × Days held

Note: Wednesday nights typically incur 3x swap (to cover the weekend).

Example:
  Short EUR/USD, 1 standard lot
  Broker swap rate for short: −0.5 points (you pay)
  Pip value: $10
  Held for 5 nights (including 1 Wednesday = 3x night)

  Normal nights: 4 × (0.5 × $10 × 1) = $20
  Wednesday night: 1 × (0.5 × $10 × 1) × 3 = $15
  Total swap cost: $35

How to use it

1. 1. Find your broker's swap rates

   Look in your broker's contract specifications or instrument details. Swap rates are listed as points per lot for both long and short positions. They change regularly based on central bank rates, so check before each trade.

2. 2. Enter the swap rate, lot size, and pip value

   Use the swap rate for your specific direction (long or short). Lot size is your position size. Pip value depends on the pair — use the Pip Value Calculator if you're unsure.

3. 3. Enter the number of days you plan to hold

   Count only the nights the position is open at rollover time (usually 5:00 PM New York time). A trade opened Monday and closed Thursday crosses 3 rollover points.

4. 4. Factor in the triple-swap Wednesday

   Most brokers charge triple swap on Wednesday night to account for the weekend (when markets are closed but interest still accrues). Some brokers apply triple swap on Friday instead. Check your broker's policy.

5. 5. Add swap cost to your trade plan

   If swap costs $15 over your expected hold time and your target profit is $100, that's a 15% drag on the trade. For short-term trades the impact is small. For positions held for weeks, swap can materially change the trade's economics.

Common mistakes

• ✗Ignoring swap entirely on swing trades. A position held for 10 days with a $5/night swap costs $50 — plus the triple-swap night. On a $200 profit target, that's a 25% tax you didn't plan for.
• ✗Using stale swap rates. Brokers adjust swap rates regularly based on interbank rates and their own markup. The rate you saw last month may not be the rate today. Always check before the trade.
• ✗Forgetting the Wednesday triple swap. Most traders learn about this the hard way when they see an unexplained charge on their account. Wednesday night (or Friday on some brokers) carries 3x the normal swap.
• ✗Assuming swap-free (Islamic) accounts have no cost. Many brokers replace swap with an administration fee or wider spreads. The cost still exists — it's just structured differently.