For the greatest accuracy, an online currency converter with up-to-date exchange rate information should be used to convert British pounds to U.S. dollars. On Oct. 20, 2014, the exchange rate was 1.6138 U.S. dollars to one British pound.
To convert 150 British pounds to U.S. dollars based on this exchange rate, one would multiply 1.6138 by 150 to get U.S.$242.07.
Exchange rates change throughout the day, and different exchange rates may be offered depending on whether you want to buy or sell a currency. One way to get the best exchange rate when traveling is to use an ATM machine once you arrive in your destination country, as opposed to exchanging money in your home country.