Checked bags weighing 41-50 pounds will incur a fee of $50 per bag, per direction, while checked bags weighing 51-100 pounds will result in a $100 fee per bag, per direction. Bags over 100 pounds are not accepted.

If your checked bag on Frontier Airlines exceeds the 40-pound (18.1 kg) weight limit, you will be subject to significant overweight fees. As of 2026, bags weighing between 41 and 50 pounds incur a $75 fee per direction, while bags weighing between 51 and 100 pounds incur a $100 fee per direction. Bags over 100 pounds are not accepted at all. These fees are cumulative, meaning you pay the base checked bag fee plus the overweight surcharge. Because Frontier is an ultra-low-cost carrier, they strictly enforce these limits at the check-in counter. To avoid these steep penalties, many savvy travelers use a portable luggage scale at home or "wear" their heaviest clothes onto the plane. If you realize your bag is heavy at the airport, it is often cheaper to move some items into your "personal item" (which must fit under the seat) or pay for a second bag rather than paying the $100 overweight fee, provided the second bag is booked online before you reach the gate.