Spirit Airlines has a weight restriction of 99 pounds and a size restriction of 80 linear inches on all checked and carry-on luggage as of 2015. The airline places a surcharge on checked luggage weighing more than 40 pounds or larger than 62 linear inches.
One personal item, such as a purse or small backpack, is included with the price of the flight and is limited to 16 inches by 14 inches by 12 inches. Carry-on luggage incurs an additional fee and is limited to 22 inches by 18 inches by 10 inches. The airline reserves the right to require carry-on bags be checked if they cannot be safely stowed inside the cabin.