What is 6.5 in g?

To convert 6.5 into grams (g), you need to specify the context, such as what substance you're measuring since grams are a unit of mass. If you're referring to 6.5 grams, then it is already in the desired unit. If you meant 6.5 kilograms, for example, that would be 6,500 grams, as there are 1,000 grams in a kilogram.