Forex Swap Calculator (Overnight Rollover)
Estimate the overnight swap (rollover) on a forex position from the two currencies’ interest rates, your broker’s markup, position size and direction — per night, for any number of nights and as an annual carry rate.
How it works
Swap per night = position units × exchange rate × (interest-rate differential − broker markup) ÷ 100 ÷ day basis × quote-to-account rate · long differential = base rate − quote rate · short differential = quote rate − base rate
A forex position held past the daily rollover (usually 5 pm New York time) is financed overnight: you earn interest on the currency you hold and pay interest on the one you borrowed. Brokers pass this on as the swap or rollover, after taking a markup, so both sides of a pair can be negative. Positions open over Wednesday’s rollover are usually charged three nights because spot trades settle two business days later. Brokers publish their actual swap points, which can differ from this interest-rate estimate.
Worked example
Long 100,000 EUR/USD at 1.0870 with EUR rates at 3% and USD rates at 4.5% and a 0.25% markup gives a net carry of 3 − 4.5 − 0.25 = −1.75% a year on a 108,700.00 USD position: 108,700 × −1.75% ÷ 365 = −5.21 per night.
Sources: Investopedia — Rollover (forex) · Investopedia — Currency carry trade
Frequently asked questions
What is a swap in forex?
The interest paid or earned for keeping a position open overnight. It reflects the interest-rate difference between the two currencies in the pair, minus the broker’s markup.
Why is the swap tripled on Wednesday?
Spot forex settles two business days after the trade. A position held over Wednesday’s rollover settles on Monday, so it is charged for Saturday and Sunday as well.
What is a carry trade?
Buying a high-interest currency against a low-interest one to collect positive swap each night. The risk is that an adverse exchange-rate move wipes out months of interest.
Do swap-free (Islamic) accounts pay swap?
They do not charge or pay overnight interest, but brokers often replace it with a fixed fee or wider spreads after a few days.
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Educational estimate, not investment, trading or tax advice. Brokers, issuers and data providers use their own conventions, fees and figures — confirm with your broker, the issuer’s documents or a licensed adviser before acting.