spirit baggage policy charges for carry-on luggage, and there are weight and size restrictions. With handles and wheels included, carry-on luggage cannot measure more than 22 x 18 x 10 inches. Carry-on fees vary based on where and when you buy the allowance, and these bags are kept in the overhead bin. The most cost-effective way to pay for carry-ons is usually when making your reservation. If a passenger exceeds these limits at the gate, they can be asked to check their bag or incur additional fees.