In Forex: How are spread costs calculated between buy and sell prices?

In market situations, the spread is the difference between the buy and sell prices in pips. To get the spread, you subtract the bid price from the ask price. For example, if you are trading GBP/USD at 1.3087/1.309, the spread is 1.309-1.3097 which is 0.003 (3 pips).