How to pack everything into a Spirit Airlines free carry-on bag

Ultra low-cost carriers like Spirit Airlines attract travelers with incredibly low fares—think $19 one-way flights. This isn’t a trick; you really can fly at such low prices, sometimes even less if you take advantage of promotions like kids fly free deals offered by Frontier.

However, as you probably know, the total cost of flying can rise quickly with additional fees. One significant way your travel expenses can escalate is by paying for checked or carry-on luggage. If you plan to check a bag during your initial booking, be ready to spend around $30 for each checked bag and $35 for one carry-on bag each way. Extra charges apply if your bags exceed weight or size limits, ranging from $30 to $150.

But here's the good news: you don’t have to pay those fees. If you can stick to just the essentials and use a backpack or similar bag, you can enjoy your low-cost flight without the burden of extra charges that others will incur.

To be fair, I do enjoy packing my Rimowa carry-on and personal bag full when my ticket includes baggage. However, I've also learned to leave my regular full-sized carry-on behind in favor of a free Spirit Airlines-approved carry-on when needed.

When you fly with Spirit Airlines, you’re allowed to bring a personal item measuring up to 18 x 14 x 8 inches on board for free. In contrast, a full-sized carry-on will set you back at least $35, depending on when and where you buy the privilege to bring that bag on board. (Members of the $9 Fare Club enjoy slightly lower prices.)

If I’m traveling solo for a short trip on Spirit Airlines, I’m determined not to pay for a bag if I can avoid it. Instead, I’ll pack efficiently for a free personal carry-on. Here’s how to do it.

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Select the right bag

To dodge Spirit Airlines' baggage fees, the first step is selecting the right bag. I've frequently relied on my beloved Sole Society Tote, but a regular backpack can suffice as long as it adheres to their size restrictions.

I’ve noticed that small traditional backpacks, like those typically used by middle schoolers, fit well within the size limits. While many larger and trendier backpacks are technically too big, Spirit Airlines isn’t known for strictly enforcing these guidelines.

My reliable Samsonite Modern Utility Double Shot Backpack (measuring 12" x 8" x 18" and featuring a laptop compartment) has been fantastic for avoiding carry-on fees. Occasionally, I even use a Mickey backpack, which is perfect for quick trips to Disney World.

Being slightly over the size limits with a bag you’re wearing or carrying likely won’t raise any alarms with Spirit. However, veering too far from the maximum dimensions for a free personal item can lead to fees, so it’s best to avoid that. If you’re unsure where to begin, check out some of our top picks for carry-on backpacks.

Stick to the essentials

Once you've chosen your Spirit Airlines-approved personal carry-on, it’s time to fill it with your must-have items—only the essentials allowed.

For me, this typically includes my laptop, wallet, a neatly rolled change of clothes, and a few smaller bags for specific items. I keep one bag for my computer cables, another for clothing like pajamas and undergarments, a third for makeup, and a final one for toiletries.

I prefer not to have any of these items loose in my compact carry-on or mixed together. If you don’t require special toiletries or makeup, you’ll have extra room for clothes compared to my usual setup.

When packing for a free Spirit Airlines personal carry-on, you’ll likely only take one pair of shoes—the ones you're wearing. Occasionally, I manage to fit in an extra pair of flats, but that's the limit. If necessary, don’t forget to bring your coat on board, even if it’s warm where you’re departing from.

Diaper bags are complimentary

While it’s fine to limit the number of shoes or hair products you take, you don’t want to cut corners on supplies for your young children. Luckily, a diaper bag for infants can also be brought on board for free—provided you are traveling with a baby.

Always ensure you have enough formula, kid-friendly snacks, diapers, wipes, and a change of clothes for your little one during the flight. Additionally, kids can also bring a car seat and stroller at no extra cost.

Think about paying for one bag for the whole family

Only you understand your budget, but if you're flying Spirit for a short weekend getaway without small children, it’s feasible to dodge Spirit bag fees and fit everything into a free carry-on—especially if your destination is warm. However, if you’re traveling with kids or going on a longer trip, it’s worth it to pay for at least one checked or carry-on bag for the family.

Everyone can still take their free personal item, but you can also pack extra items in a larger bag that you pay to check. Just make sure to book the bag online in advance for the best rate. If you have a credit card offering annual travel credits, this could be a smart way to utilize that benefit. In fact, I'm switching my Amex airline fee credit option to a low-cost carrier for this very reason.

General tips

One downside to maximizing a free Spirit personal item is that it can get quite heavy. On a recent two-night trip, I managed to bring nearly everything I would have packed in my usual roller carry-on, but the difference was that I was lugging all that weight on my arm instead of rolling it behind me.

I estimate my bag weighed around 20 pounds, and after a while, carrying it became uncomfortable. A backpack would have been a better choice for that trip rather than a tote.

Make sure to consider the weight you'll be carrying, especially if you have any physical challenges, are traveling with young children, or need to walk a long distance before you can unpack.

Often, you can avoid paying for baggage on a Spirit Airlines flight; you just need to know how to effectively pack for the complimentary carry-on.

Additional insights by Mimi Wright.