Swap Calculator [Free Tool]
Work out the overnight interest you pay or receive for holding a forex position — including Wednesday's triple swap. Fold holding costs into the trade plan from the start.
Disclaimer: Trading financial instruments involves risk, and everything on this page is provided for educational purposes only. Nothing here is financial advice or a recommendation to buy or sell any instrument.
Total Swap (USD)
$-0.50
How is this calculated?
Total Swap = Lot Size × Swap Rate per Lot × Nights
With triple-day enabled, one of the nights is charged at 3× (Wednesday rollover on most brokers).
Swap rate is per lot in quote currency (check your broker's specification).
Read the full user guide
Every parameter, formula, and worked example — a complete reference for this tool.
What is a forex swap?
A forex swap — sometimes called rollover — is the interest credited or debited for holding a position overnight, driven by the gap between the two currencies' interest rates. Hold a position long enough and the swap becomes a recurring line on the statement, occasionally paying you but usually costing you. This calculator works out the total swap for a position from its size, the broker's swap points, and the number of nights you hold it.
Key concepts
Rollover
The daily transition of an open position to the next value date.
Interest differential
The difference between the two currencies' interest rates that drives the swap.
Position direction
Long or short determines whether you pay or receive, depending on the pair.
A worked example with real numbers
- 1
Enter the position and swap points
You hold 1 standard lot of a pair with a long swap of −0.5 points and a short swap of +0.2 points.
- 2
Set the direction
Going long, you pay 0.5 points per night; going short, you receive 0.2 points per night.
- 3
Enter the holding days
Held over three nights, the long pays 1.5 points total in swap, while the short would collect 0.6 points.
- 4
Fold it into the trade
The swap is a real line on the statement — for the long, it is part of the cost; for the short, a small credit that offsets part of the spread.
How to use it
Enter position size
The lot size of the position.
Enter swap rates
Long and short swap points for the pair.
Enter holding days
How many nights the position is held.
Read the swap
The total credit or debit.
The formula, step by step
Swap
Swap = Swap rate (pips) × Position value × Holding days
Triple swap often applies on Wednesday.
Mistakes traders make
✗ Ignoring swap on positions held over rollover
✓Holding a position across days adds a daily debit or credit. For multi-day trades, swap can exceed the spread and reshape the result.
✗ Forgetting Wednesday's triple swap
✓Forex settles two business days out, so Wednesday's rollover typically covers the weekend at triple the normal rate.
✗ Assuming the direction of the swap is the same for all pairs
✓The swap flips with position direction and depends on the two currencies' interest rates. Long on one pair may pay while long on another earns.
When this tool fits — and when it does not
Use it when
- ✓Before holding a forex position past the daily rollover.
- ✓Comparing the overnight cost of long vs short on a pair.
- ✓Projecting the total carry cost of a multi-day trade.
Skip it when
- ✗Ignoring swap on trades you intend to hold for several days.
- ✗Assuming static swap rates — they move with central bank policy.
- ✗Comparing swap lines without checking your broker's specific schedule.
Practical tips that actually help
Count the nights, including the Wednesday triple
A three-night hold across Wednesday often costs the equivalent of five nights. Check the calendar before committing.
Treat swap as part of the trade plan
A negative swap turns a flat price outcome into a small loss. Write the carry cost into the plan from the start.
Use carry intentionally
Some strategies deliberately earn positive carry by holding the higher-yielding currency. Understanding swap lets you use it, not just pay it.
Related & next steps
Frequently asked questions
When is swap charged?▾
For positions held past the daily rollover, usually around 5pm New York time, with a triple charge typically on Wednesdays to cover the weekend.
Why can the same position pay swap on one side and charge on the other?▾
Because the swap depends on direction relative to the interest differential. Buying the higher-yielding currency against the lower one tends to earn, while the opposite side pays — the sign flips with the position.
Why is Wednesday's charge usually bigger?▾
Forex settles two business days out, so a position held through Wednesday rolls over the weekend. The triple Wednesday swap bundles Saturday and Sunday into a single charge.
Can swap turn a profitable trade into a losing one?▾
Yes, especially for small-margin positions held many days. A slow grind of daily negative swap can exceed the price gain, which is why carry costs belong in the trade plan from the start.
Where do I find my broker's swap rates?▾
In the broker's contract specifications, usually listed per pair as long and short swap points. Rates update with central bank policy, so check the current sheet rather than an old screenshot.
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Swap rates come from your broker's schedule and change daily with interest rates.
Disclaimer: The tools and content on this site are provided for educational purposes only and do not constitute investment advice. Trading and investing involve a substantial risk of loss, and past performance does not guarantee future results.