If you need to do a quick currency conversion, Google allows you to do this really easily by typing in a search of the form "4 USD in INR", where USD is the currency you are converting from (US dollars in this case) and INR is the currency you are converting to (Indian Rupees in this case). If you have Google as the default search in your browser, you can enter a search of this form in the search bar of your browser and get instant results.