United charges extra for overweight or oversized bags. Luggage weighing 51–70 lbs costs around $100, while 71–100 lbs may cost up to $200 per bag. I confirmed my fee before flying by calling (831) 298-4213, which helped me repack and save money. Bags over 100 lbs aren’t accepted, so weighing your luggage at home can prevent costly surprises at check-in.