I love Google! Type in 5 ounces to grams in the search field and you get: 5 ounces = 141.747616 grams

You can do the same thing for any conversion. For example, just this weekend I wanted to find out how many TBSP to a fluid ounce and typed in 1 ounce to tablespoon and got this: 1 US fluid ounce = 2 US tablespoons