Source for automotive wire by the foot?

[mc1984ss]

I just purchased a handful of different wire from the place I always buy my electrical supplies from . I need to measure the wire but I'm afraid it's undersized for what it's "supposed" to be. I see that wirebarn.com sells by the foot and apparently US made. Del city only seems to sell in big quantities. Who do you use and who do you like for wire? . The wire leads omy cooling components fan had the wire gauge printed right on it so that's what I ordered. What I received appears to be smaller, not just the insulation.
Thanks in advance