Since 1 US Dollar is equal to 0.790684 Guernsey Pounds, we could say that n United States Dollars are equal to 0.790684 times n Guernsey Pounds. In other words, we could use the following formula:
Guernsey Pounds = United States Dollars x 0.790684
For example, let's say that we want to convert 2.0 United States Dollars to Guernsey Pounds. Then, we just replace United States Dollars in the abovementioned formula with 2.0:
Guernsey Pounds = 2.0 x 0.790684
That is, 2.0 United States Dollars are equal to 1.581368 Guernsey Pounds.