You seem to have missed the convenience of secondary definitions using SI. Using SI, 1 J = 1 N * 1 m = 1 W * 1 s. You can't do the same with calories, miles,

You seem to have missed the convenience of secondary definitions using SI. Using SI, 1 J = 1 N * 1 m = 1 W * 1 s. You can't do the same with calories, miles, horsepower, and other Imperial units.