Generally, the simplest way to get a rough estimate of the range of any aircraft is to take the fuel capacity and divide it by the fuel burn at cruise, then multiply that by it's true airspeed.
This, however, would only yield a rough (and optimistic) estimate, because the actual range has several other variables, wind, suitable alternates, and a required reserve would all subtract from this number.
The refrence most light airplane pilots use is time. I know my plane can generally fly 4 1/2 hours before I need more go juice. However far I can get in those four hours depends on the weather, wind, and available alternates.
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