Allegiant Air Carry-On Rules: The 2025 Guide

Allegiant Air has built its reputation on offering some of the lowest fares in the U.S. If you’ve ever searched for flights to smaller cities or popular vacation destinations, chances are you’ve seen Allegiant’s prices undercut the competition by a wide margin. But there’s a catch — Allegiant, like Spirit and Frontier, is a budget airline that makes up for low base fares by charging extra for almost everything else. And one of the biggest areas where travelers get caught off guard is baggage.

If you’re used to flying with airlines like Delta, United, or Southwest, you probably assume a carry-on bag is included in your ticket. Not so with Allegiant. While you do get a free personal item, any larger carry-on bag that goes into the overhead bin comes with an additional fee. What’s more, the price you pay depends on when you add that carry-on. If you wait until you’re already at the airport, the fee can be steep — sometimes more than the ticket itself.

Why does this matter? Because Allegiant’s flights are often targeted at budget-conscious travelers or families looking to save money on vacation. If you’re not aware of the baggage rules ahead of time, that cheap $49 flight can quickly turn into a $150 one once you tack on carry-on and seat fees. For families especially, costs can snowball if each person needs a carry-on.

The good news is that with a little planning, you can avoid these surprise charges. Allegiant publishes clear rules about what counts as a personal item versus a carry-on, and if you know the sizes and fees ahead of time, you can pack smarter and book strategically.

In this guide, I’ll walk you through everything you need to know about Allegiant Air’s carry-on rules. From exact size limits and baggage fees to smart packing hacks and product recommendations, you’ll learn how to fly Allegiant without draining your wallet.

Allegiant Carry-On Size & Weight Limits

Allegiant Air, like most budget carriers, is very particular about what counts as a carry-on bag. The rules are designed to maximize revenue while still giving passengers a choice: travel with just a free personal item, or pay extra for overhead-bin space.

Here are the official limits for carry-on luggage on Allegiant:

• Maximum Carry-On Size:
  22 x 14 x 9 inches (56 x 36 x 23 cm) including wheels, handles, and side pockets.

• Where it goes: Overhead bin.

• Weight Restrictions: Allegiant does not publish an official weight limit for carry-on bags. However, as with Spirit and Frontier, the bag must be light enough for you to lift into the overhead bin without help from a flight attendant.

This size allowance is fairly standard compared to legacy airlines like Delta or United, but the difference is that Allegiant charges for carry-ons while those airlines usually include them.

Enforcement at the Gate

Allegiant is strict when it comes to enforcing bag sizes. At check-in counters and boarding gates, you’ll see the familiar metal sizer bins where passengers may be asked to test their bags. If your carry-on doesn’t slide in easily, you’ll have to pay the full carry-on fee on the spot — which can be as high as $75 or more if you wait until the gate.

Real-world example: I’ve seen travelers try to sneak in slightly oversized roller bags, only to be stopped at the boarding line. Even if the bag was just an inch too big, Allegiant staff insisted it be checked as a paid carry-on. Since Allegiant’s profit margins depend on fees like this, gate agents are trained to catch oversized baggage.

Why This Matters

The size rules themselves aren’t unusual — most airlines use similar limits. What makes Allegiant different is that carry-ons aren’t automatically included in your fare. If you plan on bringing anything bigger than a backpack or purse, you need to factor in the extra cost when booking. Otherwise, your “cheap” flight could become much more expensive.

Pro Tip: If you’re buying new luggage for Allegiant flights, look for bags marketed as “22-inch carry-ons.” Always measure yourself though, since some brands exaggerate. Even half an inch can mean the difference between fitting and paying up.

Personal Item Rules

When you fly Allegiant, your personal item is the only bag you can bring for free. That’s right — no complimentary roller bag in the overhead bin. Allegiant follows the same model as Spirit and Frontier: one free small bag, anything larger will cost you.

Here’s the official rule:

• Maximum Personal Item Size: 16 x 15 x 7 inches (40 x 38 x 18 cm)

• Must fit completely under the seat in front of you.

That size might look decent on paper, but in reality it’s smaller than most standard backpacks. Think laptop bag, slim daypack, purse, or a compact duffel. Anything even slightly bigger could be flagged as a paid carry-on.

Examples of Acceptable Personal Items:

• Laptop bag or messenger bag 💼

• Medium-sized purse 👜

• Small backpack 🎒

• Soft-sided tote bag 🛍️

What Often Gets Flagged:

• Large school-style backpacks stuffed to capacity

• Duffel bags that look more like mini suitcases

• Small rolling bags marketed as “underseat” but too tall or wide

Why Enforcement is Strict

Allegiant’s business model depends heavily on baggage fees. That means gate agents are trained to enforce the size restrictions closely. If your personal item looks oversized, they may ask you to test it in the sizer bin. If it doesn’t fit, it immediately becomes a paid carry-on.

And here’s the kicker: if you wait until the gate to be told your bag is too big, you’ll be paying the highest carry-on fee possible.

Smart Traveler Tips

1. Buy a bag designed for Allegiant’s dimensions — don’t rely on your everyday backpack. There are travel backpacks and duffels sized exactly to 16x15x7.

2. Don’t overstuff it — even if the bag’s dimensions are fine, bulging zippers or an awkward shape could get you flagged.

3. Soft-sided bags are better — they can squish under the seat, while rigid bags can’t.

4. Keep valuables and essentials inside — since this is your only guaranteed free bag, make it count.

The bottom line: if you want to truly fly Allegiant on the cheap, mastering the personal item rule is essential. Travelers who can live out of one small bag consistently save the most money.

Allegiant Carry-On Fees

If you only remember one thing about Allegiant baggage rules, let it be this: your ticket price does not include a carry-on bag. Allegiant treats carry-on luggage as an add-on, and the cost depends on when you purchase it. Buy early and you’ll pay less, wait until you’re boarding and you’ll pay the maximum.

Allegiant’s Fee Breakdown

• At booking (cheapest): Around $20–$35 each way.

• Before check-in (online): Around $45.

• At the airport check-in counter: $55–$60.

• At the gate (most expensive): $75 or more.

These numbers aren’t fixed, because Allegiant uses a variable pricing model. The route, season, and demand can all affect how much you’re charged. But the pattern is always the same: the earlier you add your carry-on, the less you’ll pay.

Why the Fees Vary

Allegiant operates on a low-cost model where the airfare itself is stripped down to just your seat and a personal item. Everything else is considered “optional” and comes with a fee. The psychology behind the escalating prices is intentional: Allegiant wants you to add your carry-on at booking, because it’s cheaper for them operationally if they know your baggage situation in advance.

Gate Check Shock

One of the most frustrating experiences for Allegiant passengers is being caught at the gate with an oversized personal item. If it doesn’t fit in the under-seat sizer, Allegiant immediately classifies it as a carry-on and charges you the highest possible fee — usually $75 or more. For budget travelers who bought a $49 ticket, this feels like a slap in the face.

Example: I’ve seen passengers argue with gate agents over a backpack that looked slightly too big. It didn’t matter — once Allegiant says it’s a carry-on, you either pay up or you don’t board. There’s no negotiating at that point.

Bundles Can Help

Allegiant sometimes offers bundles, like its “Trip Flex” or vacation packages, that include baggage options at a discounted rate. If you know you’ll need a carry-on and possibly a checked bag, it’s often worth comparing the bundle price against adding bags individually.

Smart Traveler Tips

1. Always add your carry-on at booking if you know you’ll need one.

2. Double-check your personal item size so you don’t get upgraded to a paid carry-on at the gate.

3. Travel light when possible — the biggest savings come from using only a personal item.

4. Compare final costs — sometimes a major airline with a free carry-on ends up cheaper than Allegiant once baggage is added.

The key is planning. Allegiant isn’t trying to trick you — they publish their fees clearly. But if you don’t pay attention until you’re at the airport, you’ll pay the price, literally.

Packing Smart for Allegiant

If you want to beat Allegiant at its own game, the smartest thing you can do is learn how to pack light. Since only a small personal item is free, most travelers either pay for a carry-on or figure out how to live out of one compact bag. With the right approach, you can absolutely travel for several days with just a personal item — and save yourself $50–$75 per flight in the process.

1. Choose the Right Bag

Your personal item is the single most important piece of gear you’ll bring on Allegiant. It has to fit within 16 x 15 x 7 inches and slide easily under the seat. A school backpack or an oversized tote might look fine at home but could get flagged at the airport.

Best choices:

• Slim travel backpacks designed for under-seat storage

• Compact duffel bags with soft sides that compress

• Laptop bags with extra compartments

👉 Matein Travel Backpack is a popular option that stays within Allegiant’s limits but still fits 2–3 days of clothing.

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2. Roll, Don’t Fold

Folding wastes space. Rolling clothes tightly lets you fit more into a small bag and keeps things wrinkle-free. A pair of jeans, 2 T-shirts, and a hoodie rolled together can fit in a single compression cube.

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3. Use Compression Packing Cubes

Compression cubes are lifesavers for Allegiant travelers. They squeeze out excess air and help you fit much more in a small personal item.

👉 Tripped Travel Gear Compression Cubes are lightweight and perfect for this.

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4. Wear Your Bulkiest Items

Traveling with boots or a thick jacket? Don’t waste bag space. Wear them on the plane. You can always take your jacket off once seated and use it as a blanket or pillow.

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5. Simplify Toiletries

Since you don’t have space for full-size bottles, switch to travel bottles or solid alternatives like shampoo bars.

👉 LiquiSnugs Travel Bottles are TSA-approved, leak-proof, and easy to refill.

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6. Don’t Overstuff

Even if your bag technically fits the dimensions, a bulging zipper could get you flagged. Leave a little breathing room so it looks compact.

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Pro Hack: If you’re traveling with a companion, divide items between both of your free personal bags. Two small bags are cheaper than one oversized one.

Packing for Allegiant is all about strategy — with the right gear and mindset, you can skip the fees and still bring everything you need.

Liquids & Toiletries

When you’re flying Allegiant, your liquids and toiletries have to meet the same TSA 3-1-1 rule that applies to all U.S. airlines. Allegiant doesn’t add any extra restrictions of its own, but because most travelers on Allegiant only bring a personal item, it’s extra important to pack smart.

The TSA 3-1-1 Rule

Here’s the breakdown:

• 3.4 ounces (100 ml) max per container – no exceptions.

• 1 quart-sized clear, resealable plastic bag – all liquids must fit inside.

• 1 bag per passenger – you can’t bring multiple quart bags.

Anything larger than 3.4 ounces will get tossed at security, even if the bottle is almost empty.

Common Items That Count as Liquids or Gels

This rule applies to more than just shampoo. Many travelers get caught off guard because TSA counts the following as liquids/gels:

• Toothpaste

• Mascara

• Hair gel and pomade

• Creams and lotions

• Peanut butter, jam, or other spreads (if you pack snacks)

Allegiant-Specific Considerations

Since Allegiant flights often cater to short trips and vacation destinations, many travelers try to fit all toiletries into their one free personal item. This makes the 3-1-1 rule feel even stricter. If you’re not careful, half your bag could be taken up by toiletries alone.

Pro Tips for Toiletries on Allegiant:

1. Use refillable travel bottles – LiquiSnugs Travel Bottles are TSA-approved and leak-proof.

2. Switch to solids – shampoo bars, conditioner bars, and solid deodorants don’t count toward your liquid limit.

3. Buy at your destination – if it’s a short vacation, grab toiletries at a local shop instead of packing them.

4. Keep it minimal – ask yourself what you really need for a 2–3 day trip versus what can stay home.

Why It Matters More on Allegiant

Unlike bigger airlines, you can’t “spread out” your liquids between a personal item and a carry-on without paying extra. That means every drop counts. The savviest Allegiant travelers are the ones who streamline their toiletries, freeing up bag space for clothes and electronics.

Electronics

Flying Allegiant with electronics is pretty straightforward, but because the airline offers a no-frills experience, how you pack and prepare your devices can make a huge difference in comfort. Unlike bigger carriers, Allegiant doesn’t provide in-flight entertainment screens, free WiFi, or seatback charging. That means your electronics are your lifeline for passing the time, and you’ll want to plan accordingly.

TSA Rules for Electronics

• Laptops, tablets, and e-readers must be removed from your bag and placed in a separate bin when going through security.

• Small electronics like phones, cameras, or headphones can stay in your bag.

• Lithium batteries and power banks must go in your carry-on/personal item — never in checked luggage. This is a safety rule across all airlines.

Allegiant’s Cabin Experience

Allegiant flights are typically shorter (under 4 hours), but since they’re bare-bones, you’ll need your own entertainment. There are no built-in seatback screens, and while Allegiant has been rolling out in-flight WiFi on some planes, it’s still limited and usually comes with a fee.

Translation: if you want to watch movies, listen to music, or keep kids entertained, download everything before you board. Relying on Allegiant’s WiFi is a gamble.

How to Pack Electronics for Allegiant

1. Use a slim laptop sleeve – Instead of bringing a bulky laptop bag, slide your laptop into a thin padded sleeve inside your personal item.

2. Bring a compact power bank – Since Allegiant doesn’t guarantee outlets at every seat, a reliable power bank is a must. 👉 Anker PowerCore Slim 10000 is compact and perfect for travel.

3. Noise-canceling headphones – Allegiant cabins can be noisy, and headphones will save your sanity.

4. Keep cords organized – A cable organizer pouch keeps your chargers from becoming a tangled mess in a small bag.

Pro Hack

If you’re traveling with family or friends, distribute electronics among everyone’s personal items. Instead of one overstuffed bag, each traveler carries a device, freeing up space and reducing the risk of being flagged for an oversized bag.

In short: Allegiant doesn’t give you much, so your devices need to cover entertainment, productivity, and charging. Plan ahead, and you’ll turn a bare-bones flight into a manageable one.

Allegiant vs Other Airlines: How Do the Carry-On Rules Compare?

Allegiant Air often gets grouped with Spirit and Frontier because of its fee-heavy approach to baggage. And it’s true — Allegiant charges for overhead-bin carry-ons just like those airlines. But there are a few key differences that are worth pointing out, especially when comparing Allegiant with both other budget carriers and the larger legacy airlines.

Here’s a breakdown:

Key Takeaways

• Allegiant vs Spirit/Frontier: Allegiant’s personal item size limit (16x15x7) is smaller than Spirit’s and Frontier’s (18x14x8). This means Allegiant is stricter, giving you less wiggle room for a “free” bag. However, Allegiant’s carry-on fees are sometimes lower if purchased at booking ($20–$35 compared to Spirit’s $39–$59).

• Allegiant vs Legacy Airlines: The difference is night and day. On Delta, United, American, and Alaska, a carry-on bag is free for almost all fares (except some United Basic Economy). Allegiant charges every time. If you’re someone who always travels with a roller bag, Allegiant could easily end up costing you more than a full-service airline once baggage fees are added.

• Allegiant vs Southwest: Southwest is the complete opposite of Allegiant. Not only do you get a free carry-on, you also get two free checked bags. For travelers who pack heavy, Southwest often ends up cheaper even if the base fare looks higher.

The Bottom Line

Allegiant is cheapest if you’re a minimalist traveler who can live out of a personal item. If you know you’ll need a carry-on, compare Allegiant’s final cost (ticket + baggage) with other airlines before booking. In many cases, the difference is small, and flying a legacy carrier may give you more comfort and flexibility for nearly the same price.

Best Travel Gear for Allegiant Air

If you want to fly Allegiant without getting slapped with surprise fees, the right gear makes all the difference. Allegiant’s strict bag size limits mean you can’t just grab any backpack from home and hope it works. Investing in luggage and accessories designed for budget airlines can save you money in the long run.

Here are some top picks that Allegiant travelers swear by:

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1. Underseat Backpack (Personal Item Approved)

Matein Travel Backpack

This backpack is one of the best for Allegiant because it’s slim, compact, and specifically designed for under-seat storage. It fits within Allegiant’s 16 x 15 x 7 personal item size limits while still offering multiple compartments.

Pros:

• Fits Allegiant’s dimensions perfectly.

• Includes a laptop sleeve for work trips.

• Anti-theft pocket for valuables.

Cons:

• Space is limited if you’re traveling for more than 3–4 days.

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2. Underseat Rolling Bag

Amazon Basics Underseat Carry-On

If you prefer wheels to carrying a backpack, this under-seat roller is a great option. It slides under most airline seats, including Allegiant’s, and has just enough space for clothes and essentials.

Pros:

• Easy to maneuver through airports.

• Compact and lightweight.

• Affordable.

Cons:

• Less flexible than a backpack for squeezing into tight spaces.

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3. Compression Packing Cubes

Tripped Travel Gear Compression Cubes

When you only have one small bag, organization is key. These packing cubes compress your clothes so you can fit twice as much in Allegiant’s limited personal item space.

Pros:

• Saves a ton of space.

• Keeps your bag organized.

• Lightweight and durable.

Cons:

• Can make your bag look bulkier if overstuffed.

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4. TSA-Approved Toiletry Bottles

LiquiSnugs Travel Bottles

These silicone bottles are leak-proof, refillable, and fit perfectly into TSA’s 3-1-1 liquids rule. Ideal for Allegiant since you’ll likely be carrying toiletries in your only free bag.

Pros:

• Meets TSA rules.

• Prevents leaks.

• Reusable and eco-friendly.

Cons:

• Only enough capacity for short trips.

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5. Compact Power Bank

Anker PowerCore Slim 10000

Allegiant doesn’t guarantee power outlets on board, so a power bank is essential. This slim model is lightweight, reliable, and charges your phone multiple times.

Pros:

• Slim and portable.

• High capacity for its size.

• Trusted brand.

Cons:

• Recharging the bank itself takes a while.

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Equipping yourself with the right bag, cubes, bottles, and power bank can be the difference between traveling comfortably within Allegiant’s rules and paying steep last-minute fees.

Conclusion

Allegiant Air has built its brand on offering some of the lowest fares in the country, but the savings only hold up if you understand the baggage rules. For many travelers, the biggest surprise comes from realizing that carry-on bags aren’t free. If you show up at the airport with a roller bag and haven’t paid for it in advance, you could end up paying as much in baggage fees as you did for the ticket itself.

The key to avoiding these costs is simple: plan ahead. Know the difference between a personal item and a carry-on. Stick to Allegiant’s tight 16 x 15 x 7 inch personal item allowance if you want to travel free of extra charges. If you do need a carry-on, always add it at booking to lock in the cheapest price. Waiting until the gate is a costly mistake.

But Allegiant isn’t all bad news. If you’re willing to pack light, this airline can save you a lot of money, especially on short trips or weekend getaways. By rolling clothes, using compression cubes, downsizing toiletries, and wearing bulky items on the plane, you can make the most of your free personal item. And if you need a bit more space, investing in the right underseat bag or backpack designed for Allegiant’s dimensions will keep you safe from gate check fees.

At the end of the day, Allegiant is all about trade-offs. You’re giving up some comfort and flexibility in exchange for lower ticket prices. If you’re a traveler who values minimalism, Allegiant can work in your favor. But if you’re someone who always needs multiple bags, you may find that the “cheap” Allegiant fare isn’t so cheap after all.

So the bottom line is this: pack smart, plan ahead, and know the rules. If you do, Allegiant Air can be one of the most budget-friendly ways to get to your destination. If not, you might end up wishing you had booked with another airline.