The size restrictions seem pretty uniform throughout, but the weight seems to vary a lot. I never pack 40 lbs in a carry on. If I can't lift it, I don't pack it. That's my self imposed rule. I can lift 20 lbs, and I hope to get away with it. On the way back though I am going to stay just below 18 lbs. I am also planning on wearing a sweater and a jacket, and carry the camera in my purse. They have not yet thought of weighing womens purses.......I should not put ideas in their heads.