Swap Calculator — Forex Overnight Rollover Fee Tool

Using the swap calculator takes under a minute. Enter your trade size in lots (one standard lot = 100,000 units), the current pair price, and the annual interest rates for both the long currency and the short currency. Select whether your trade is Long (buy) or Short (sell), then set the number of nights you plan to hold the position. Click "Calculate Swap Cost" to see the result.

The calculator shows your daily swap in USD, plus projections for one week, one month, and the exact number of nights you entered. A green badge means you receive the swap (positive carry); a red badge means you pay it (negative carry). Interest rates are usually available on your broker's contract specification page.

Note: On Wednesdays, most brokers apply a triple swap (3× the daily rate) to compensate for the weekend when markets are closed. The "weekly" figure in this calculator reflects 7 daily rollovers and therefore already includes this effect proportionally.

This calculator uses the interest rate differential method, which is the academically correct basis for swap pricing:

1. Notional value: Notional = Lots × 100,000 × Pair Price
2. Rate differential (long position): Rate Diff = Long Currency Rate − Short Currency Rate
3. Rate differential (short position): Rate Diff = Short Currency Rate − Long Currency Rate
4. Daily swap: Daily Swap = Notional × (Rate Diff / 100) / 365
5. Total swap: Total = Daily Swap × Number of Nights

A positive Daily Swap means you receive this amount each night (positive carry). A negative value means you pay it. The sign depends on which currency in the pair carries the higher interest rate and which direction you are trading.

Brokers may quote swap rates directly in pips (the "swap rate" column on their platform). Those rates include broker markup and may differ slightly from the pure interest rate differential shown here. Always verify with your broker's published swap schedule for live trading.

Example 1 — Positive Carry: Long USD/JPY

You buy 2 lots of USD/JPY at 149.50. The USD interest rate is 5.25% and the JPY rate is 0.1%. You plan to hold for 5 nights.

• Notional = 2 × 100,000 × 149.50 = $29,900,000
• Rate differential (long) = 5.25% − 0.1% = 5.15%
• Daily swap = $29,900,000 × 0.0515 / 365 = +$4,218.49/day
• Total for 5 nights = $4,218.49 × 5 = +$21,092.47 (receive)

Because USD carries a much higher interest rate than JPY, a long USD/JPY position earns significant positive carry — a classic "carry trade" setup.

Example 2 — Negative Carry: Long EUR/USD

You buy 1 lot of EUR/USD at 1.0850. The EUR rate is 3.75% and the USD rate is 5.25%. You hold for 7 nights.

• Notional = 1 × 100,000 × 1.0850 = $108,500
• Rate differential (long) = 3.75% − 5.25% = −1.50%
• Daily swap = $108,500 × (−0.015) / 365 = −$4.46/day
• Total for 7 nights = −$4.46 × 7 = −$31.23 (pay)

Because the USD funding rate exceeds the EUR rate, holding long EUR/USD costs you swap fees each night. Over weeks and months this adds up, and is an important cost to factor into any carry-sensitive trading strategy.