Calculate Swap Rate

Forex Swap Rate & Rollover Calculator

Calculation Results

Daily Swap Value (Long):

Daily Swap Value (Short):

Annual Projected Swap (Long):

*Results are estimates based on the interest differential and standard 365-day year. Brokers may apply triple swap on Wednesdays.

function calculateSwap() { var contractSize = parseFloat(document.getElementById('contractSize').value); var lots = parseFloat(document.getElementById('lotVolume').value); var baseRate = parseFloat(document.getElementById('baseRate').value); var quoteRate = parseFloat(document.getElementById('quoteRate').value); var markup = parseFloat(document.getElementById('brokerMarkup').value); var exchangeRate = parseFloat(document.getElementById('exchangeRate').value); if (isNaN(contractSize) || isNaN(lots) || isNaN(baseRate) || isNaN(quoteRate) || isNaN(markup) || isNaN(exchangeRate)) { alert("Please enter valid numerical values."); return; } // Formula: (Contract Size * Lots * (Interest Rate Differential / 100) / 365) // Long Swap: (Base – Quote – Markup) // Short Swap: (Quote – Base – Markup) var totalVolume = contractSize * lots; var longDiff = (baseRate – quoteRate – markup) / 100; var shortDiff = (quoteRate – baseRate – markup) / 100; var dailyLong = (totalVolume * longDiff) / 365; var dailyShort = (totalVolume * shortDiff) / 365; // Convert to Quote Currency value (usually what's reflected in P/L) // Note: In some pairs, the result is already in the quote currency. document.getElementById('longSwapResult').innerText = dailyLong.toFixed(2) + " units"; document.getElementById('shortSwapResult').innerText = dailyShort.toFixed(2) + " units"; document.getElementById('annualLong').innerText = (dailyLong * 365).toFixed(2) + " units"; document.getElementById('swap-result-container').style.display = 'block'; }

What is a Swap Rate?

In the foreign exchange market, a swap rate (also known as rollover interest) is the interest added to or deducted from a trading account for holding a position overnight. Because every currency trade involves borrowing one currency to buy another, interest is paid on the borrowed currency and earned on the purchased currency.

How the Swap Calculation Works

The swap value is primarily determined by the interest rate differential between the two countries whose currencies are being traded. If you are "Long" a currency with a higher interest rate than the one you are "Short," you typically earn interest (Positive Swap). Conversely, if the currency you bought has a lower interest rate, you pay interest (Negative Swap).

The Core Formula:

Daily Swap = (Contract Size × Lots × (Interest Rate Differential) / 365)

Key Factors Influencing Swap Rates

• Central Bank Rates: Policy changes by the Fed, ECB, or BoJ directly shift swap calculations.
• Broker Markups: Most retail brokers subtract a small fee (markup) from the interest differential, which can turn a small positive swap into a negative one.
• Triple Swap Wednesdays: Since Forex markets settle on a T+2 basis, positions held over Wednesday night usually incur three days' worth of swap to account for the weekend.

Example Calculation

Imagine you are trading 1 Standard Lot (100,000 units) of a pair where the Base Currency has a 5.0% interest rate and the Quote Currency has a 2.0% interest rate. Your broker charges a 0.25% markup.

1. Interest Differential: 5.0% – 2.0% – 0.25% = 2.75%
2. Annual Swap Value: 100,000 × 0.0275 = 2,750 units
3. Daily Swap Value: 2,750 / 365 = 7.53 units per day

If you were Short the same pair, the calculation would be (2.0% – 5.0% – 0.25%) = -3.25%, resulting in a daily deduction of approximately 8.90 units.