What is the cash value of frequent flier miles?

You usually can't cash them in but need to actually use them so, strictly speaking, they have no CASH value. As a rough guide, though, when used they are worth an average of 1 cent per point. The value actually obtained depends on what program you're with and how you use them. Buying low cost items, you'll find the points are worth considerably less than if you were to use them for long distance flights. To determine value for specific use, divide number of points needed for something into the number of dollars you'd need to spend to get the same thing. I choose to save them up and use them for overseas flights where they're worth about 4 cents a point.