How much does a semi truck weigh with no cargo?

16,000 - 20,000 lbs usually for the front part ("truck", "tractor", "cab"). But the empty trailer adds several tons more. For example a 53 foot long simple box ("van") trailer weighs 10,000-15,000 with nothing in it. So a whole 65 foot long empty system (truck and trailer) weighs over 30,000 lbs. Shorter box, flatbed, and covered wagons systems would weigh less. Systems with an extra long truck or specialized systems, like some of those with tank and pumping equipment, may weigh more. Adding to this answer. I have a 2003 kenworth w900 with a stepdeck trailer and i weigh 32,000 empty.