Trading knowledge libraryHow to Calculate Swap CostTrading Math
Trading Math
How to Calculate Swap Cost
Swap is the charge or credit for holding a trade overnight, and the specification gives it in points per lot per night. This paper shows you how to turn that figure into money at your trade size, what one night took from a real trade carried into the next day, how the nights of a week are counted, and where the platform writes the same sum the morning after.
Swap is the charge, or the credit, for holding a trade past midnight on the platform's clock — the interest on the currency you owe, less the interest on the currency you hold, with the broker's cut. The symbol's specification gives it in points per lot per night, one figure for a buy and one for a sell. A point is a tenth of a pip, the fourth decimal place, and on the euro against the dollar a point is worth one dollar per lot. So the sum is points times lots times the point value: a buy of one lot at minus 7 points costs seven dollars a night, and a tenth of a lot seventy cents.
One real trade, held one night
Here is the sum on a real trade. One lot bought at the open of 3 September 2026, 1.15872, was carried across midnight and sold at the close of 4 September, 1.16136 — a pip is the fourth decimal place, so 26.4 pips, $264. One midnight was crossed, so one night's swap was charged: minus 7 points times one lot times a dollar, seven dollars, and the trade closed with $257. Sold on the same day it was bought, the trade would have paid no swap at all; the charge is for midnights crossed, not for hours held.
