Swap Calculator
Calculate swap with our free Swap Calculator. Compare rates, see projections, and make informed financial decisions. Free to use with no signup required.
Formula
Swap = Lots × Contract Size × Swap Rate × Point Value × Days
The daily swap charge or credit equals the lot size times the contract size times the swap rate in points times the point value. This is multiplied by the number of days held, with an extra 2 days added for each Wednesday rollover (triple swap) to account for the weekend.
Worked Examples
Example 1: EUR/USD Long Position — 7 Days
Problem: You hold 2 standard lots of EUR/USD long for 7 days. Swap long = -3.5 points, swap short = +1.2 points. Account in USD (exchange rate = 1).
Solution: Daily swap (long): 2 × 100,000 × (-3.5) × 0.0001 = -$70.00/day\nTotal for 7 days: -$70 × 7 = -$490.00\nWith Wednesday triple: 1 Wednesday = 2 extra days\nAdjusted total: -$70 × 9 = -$630.00\nAnnual cost if held: -$70 × 365 = -$25,550
Result: Daily: -$70.00 | 7-day total: -$490.00 | With Wed triple: -$630.00
Example 2: AUD/JPY Carry Trade — 30 Days
Problem: You hold 1 standard lot of AUD/JPY long for 30 days. Swap long = +6.8 points. Account in USD, AUD/USD = 0.65.
Solution: Daily swap: 1 × 100,000 × 6.8 × 0.0001 = ¥68/day\nIn USD (÷ exchange rate): assume swap already in quote ccy\n30-day total: ¥68 × 30 = ¥2,040\nWith 4 Wednesdays (8 extra days): ¥68 × 38 = ¥2,584\nAnnual income: ¥68 × 365 = ¥24,820
Result: Daily: +¥68 | 30-day: +¥2,040 | Annual: +¥24,820
Frequently Asked Questions
What is a swap (rollover) in forex trading?
A swap, also called a rollover or overnight interest, is the interest rate differential between the two currencies in a forex pair that is charged or credited to your account when you hold a position overnight. Every currency has an associated interest rate set by its central bank. When you buy a currency with a higher interest rate and sell one with a lower rate, you earn a positive swap (credit). When you sell the higher-yielding currency and buy the lower-yielding one, you pay a negative swap (debit). Swaps are applied at the end of each trading day, typically at 5:00 PM Eastern Time (New York close). The exact swap rates are set by individual brokers and may differ from the theoretical interest rate differential due to broker markups, liquidity conditions, and administrative costs.
Why is there a triple swap on Wednesday?
The triple swap on Wednesday exists because of the settlement convention in the forex market. Forex trades settle on a T+2 basis, meaning a trade executed on Monday settles on Wednesday. When a position is held overnight from Wednesday to Thursday, the settlement moves from Friday to Monday, spanning the weekend (Saturday and Sunday). Since no swaps are charged on Saturday and Sunday even though interest accrues over those days, the Wednesday rollover accounts for all three days: Wednesday night itself plus Saturday and Sunday. Therefore, if you hold a position through Wednesday at 5 PM ET, you are charged or credited three times the daily swap rate. Some brokers apply the triple swap on Friday instead, so it is important to check your specific broker's policy. This mechanism ensures total annual interest charges correctly reflect 365 days regardless of weekends.
How do brokers determine swap rates?
Brokers determine swap rates based on the interest rate differential between the two currencies in a pair, but they also apply their own markup. The base calculation uses the overnight interbank lending rates (such as SOFR for USD, EONIA/ESTR for EUR, SONIA for GBP) for each currency. The theoretical swap equals the difference between these rates, adjusted for the position direction. However, brokers typically charge a spread on both long and short swaps, meaning the positive swap you receive is lower than the theoretical value, and the negative swap you pay is higher. Some brokers offer swap-free (Islamic) accounts that comply with Sharia law by eliminating interest charges, though they may apply alternative fees. Swap rates change frequently as central banks adjust interest rates and interbank lending conditions evolve.
How do swap rates affect trading strategies?
Swap rates significantly impact several trading strategies. Carry trade strategies specifically seek to profit from positive swap rates by buying high-yielding currencies against low-yielding ones and holding positions for extended periods. For example, buying AUD/JPY when Australian rates are high and Japanese rates near zero. Swing traders who hold positions for days or weeks must factor swap costs into their profit calculations, as negative swaps can erode gains over time. Day traders who close all positions before the daily rollover time are generally unaffected by swaps. Position traders and long-term investors face the largest swap impact and should calculate the annual swap cost as a percentage of their position size. In periods of significant interest rate differentials between major economies, swap income or costs can materially affect overall trading performance.
Can you earn money from swap rates?
Yes, it is possible to earn money from positive swap rates, a strategy known as the carry trade. When you hold a long position in a currency pair where the base currency has a significantly higher interest rate than the quote currency, your broker credits your account with a positive swap each night. For example, if the swap long rate for a pair is +5 points per lot per night, holding one standard lot earns approximately $5 per day or $1,825 per year (including triple Wednesdays). However, several risks exist: currency exchange rate movements can easily wipe out swap income, central banks may change interest rates unexpectedly, and broker swap rates may be adjusted without notice. Additionally, brokers take a markup that reduces your actual earnings below the theoretical interest differential. Successful carry traders typically combine swap income with technical or fundamental analysis to also profit from favorable price movements.
How do swap rates and rollover fees work in forex?
Swap rates are interest charges or credits applied when you hold a position overnight. They reflect the interest rate differential between the two currencies in the pair. Positions earn or pay swap depending on the direction and rate differential. Wednesday swaps are tripled to account for the weekend.