My height is a175 and don't play any sport, i'm 48 years old what should be my weight?

You choose: "whatever looks and feels right to you" is still the best answer even if your athletic days are over. A man doesn't need any more body fat on his torso than is on the back of his hand. Even though you're not playing sports any more, you have asked a health-focused question and perhaps you're also staying fit in some aerobic or strength-building activity. Build & trim your body as feels best.