Forex Swap Calculator
Calculate overnight swap or rollover charges on a position held over days.
Please note: Forex trading carries a high risk of loss, amplified by leverage. Exchange rates must be entered manually — no live market data is used.
What the Forex Swap Calculator does
Swap, or rollover, is the interest adjustment applied when a forex position is held past the daily cut-off. It comes from the interest rate differential between the two currencies in the pair, adjusted by your broker's markup.
Formula
Swap = Rate per lot × Lots × NightsTriple-swap days count as three nights each
Inputs explained
| Input | Unit | Required | Notes |
|---|---|---|---|
| Trade size (lots) | number | Yes | Accepts more than 0. |
| Lot type | one of 4 options | Yes | — |
| Swap rate per standard lot per night | number | Yes | From your broker, quoted per standard lot. Negative means you pay, positive means you earn. |
| Nights held | number | Yes | Accepts 0 or more. |
| Triple-swap days included | number | Optional | Usually Wednesday, charged 3×. Accepts 0 or more. |
| Currency | one of 10 options | Optional | — |
How to use it
- Choose Lot type and Currency.
- Enter Trade size (lots), Swap rate per standard lot per night and Nights held.
- Optionally add Triple-swap days included.
- Select Calculate.
Worked example
Holding 1 lot with a −$4.20 nightly swap for 5 nights including one Wednesday.
- Lots
- 1
- Swap rate
- -4.20
- Nights
- 5
- Triple days
- 1
5 + 2 = 7 effective nights × −$4.20 = −$29.40 paid.
Frequently asked questions
Can swap ever be positive?
Yes, when you hold the higher-yielding currency and the differential exceeds the broker markup. This is the basis of the carry trade, though it exposes you to currency risk.
How do I avoid swap entirely?
Close positions before the daily rollover, or use a swap-free account if your broker offers one.