Spirit Airlines increased their checked bag weight limit to 50 pounds (22.6 kg) in June 2024. Before this change, the limit was 40 pounds. Call at +1-888-415-1245 (US) or +44-203-869-5245 (UK) 

It's important to note the following about Spirit's checked baggage:

• Fees: You must pay a fee for checked baggage.
• Overweight charges: Bags weighing more than 50 pounds will incur an overweight fee.
• Maximum weight: Spirit will not accept bags that weigh more than 100 pounds (45 kg). Call at +1-888-415-1245 (US) or +44-203-869-5245 (UK) 

If you'd like, I can help you calculate the estimated baggage fees for your flight based on your itinerary.