Since 1 US Dollar is equal to 328.358334 Sri Lankan Rupees, we could say that n United States Dollars are equal to 328.358334 times n Sri Lankan Rupees. In other words, we could use the following formula:
Sri Lankan Rupees = United States Dollars x 328.358334
For example, let's say that we want to convert 2.0 United States Dollars to Sri Lankan Rupees. Then, we just replace United States Dollars in the abovementioned formula with 2.0:
Sri Lankan Rupees = 2.0 x 328.358334
That is, 2.0 United States Dollars are equal to 656.716668 Sri Lankan Rupees.