Frontier personal item

Frontier’s free personal item is 18 × 14 × 8 inches, must fit under the seat, and is included on every fare — including Basic. Anything larger can be treated as a carry-on (paid on Basic/Standard unless you have Economy or higher). Frontier’s personal-item sizer is strict; measure the packed bag before you fly.

Field	Value
Max dimensions (in)	18 × 14 × 8 in
Max dimensions (cm)	CoC: 20 × 35 × 45 cm (maps to ≈ 8 × 14 × 18 in order)
Placement	Under the seat (not overhead)
Cost	Free on all fares — Basic, Standard, Economy, Premium, Business
Weight	Bag-options messaging: up to 35 lb · CoC may be silent — confirm before treating 35 lb as a hard CoC limit
If oversized	Treated as carry-on + applicable fee (dynamic — confirm in booking; often higher at gate)
Carry-on contrast	24 × 16 × 10 in, 35 lb; paid on Basic/Standard — carry-on size
Allowed examples	Backpack, tote, laptop bag, slim weekender that still fits the sizer when packed
Basic interaction	Basic = personal item only for a free cabin bag
Sizer strictness	Strict — gate enforcement is common

Note on CoC carry-on cm: The carry-on sibling notes CoC 114 cm is likely wrong for a 24-inch bag. That figure belongs on carry-on size; this page uses CoC 20 × 35 × 45 cm for the personal item after aligning order with 18 × 14 × 8 in.

United publishes a personal-item box around 17 × 10 × 9 (United personal item); Delta emphasizes under-seat fit (Delta personal item). On Frontier Basic, the free 18 × 14 × 8 bag is the ULCC lifeline — do not confuse it with Frontier’s larger (often paid) carry-on.

• Personal item: always free (18 × 14 × 8), all fares.
• Full carry-on: free only with Economy / Premium / Business (or a purchased add-on on Basic/Standard). Exact add-on $ is dynamic — check optional services / booking.
• Checked bags: dynamic paid unless Business (two checked up to 50 lb each) or eligible Military (1 personal + 1 carry-on + 2 checked free).
• Board First is seating/boarding priority, not a personal-item substitute and not a free pass for an oversized under-seat bag.

Current names: Basic, Standard, Economy, Premium, Business (bundles).

1. Soft bags expand. A backpack that fits empty can fail 18 × 14 × 8 when packed — Frontier’s sizer does not care about marketing photos.
2. Oversized personal item → carry-on fee. Pricing follows the booking → airport → gate ladder; waiting until the gate is usually the expensive mistake.
3. Weight: bag-options may cite up to 35 lb; if the CoC is silent, confirm on Frontier rather than treating 35 lb as a hard CoC limit.
4. Do not confuse carry-on dims with personal item. Frontier’s overhead max (24 × 16 × 10) looks generous next to mainline carriers — but Basic flyers only get the smaller free bag for free.
5. Gate agents enforce the sizer. “It fit last time” is not a policy.

• On Basic, pack only a true under-seat bag that measures ≤ 18 × 14 × 8 when packed.
• Measure the packed bag, not the empty listing size.
• If you need overhead space, buy the carry-on early or choose Economy+ / a higher bundle — do not wait for the gate.
• Keep liquids/tech in the personal item so a last-minute forced check of a paid carry-on does not strand essentials (when bin-full gate-check rules apply — confirm official wording).

Shop for under-seat backpacks and slim totes marketed at or under 18 × 14 × 8 inches, then tape-measure the packed bag. Angle: bags that fit the Frontier personal item sizer.

Disclosure: As an Amazon Associate, BagRule may earn from qualifying purchases. Suggestions are optional — always verify against Frontier’s sizer.

Fit goal	What to look for
Free Frontier personal item	External dims ≤ 18 × 14 × 8 in; fits under seat when packed
Paid / bundled carry-on	≤ 24 × 16 × 10 in; ≤ 35 lb — see carry-on size

(Soft Amazon: up to 1–2 under-seat / sizer-fit product cards may be placed here in production. Keep fee discussion non-commercial.)

What is the Frontier personal item size?
18 × 14 × 8 inches. The CoC also lists 20 × 35 × 45 cm (same box, different axis order). It must fit under the seat.

Is a personal item free on Frontier Basic?
Yes. Every fare includes one free personal item. Basic does not include a free full-size carry-on.

What if my personal item doesn’t fit the Frontier sizer?
It can be treated as a carry-on and charged the carry-on fee (often highest at the gate). Measure ahead.

Does Frontier allow a backpack as a personal item?
Yes, if it fits 18 × 14 × 8 under the seat when packed.

What’s the difference between Frontier personal item and carry-on?
Personal: 18 × 14 × 8, free, under seat. Carry-on: 24 × 16 × 10, 35 lb, overhead — paid on Basic/Standard, included on Economy+.

Do Delta and United personal-item rules differ?
United publishes about 17 × 10 × 9; Delta stresses under-seat fit (confirm dims on those pages). Frontier’s free 18 × 14 × 8 bag is especially important on Basic. See Delta personal item and United personal item.

Confirm sizes and live fees on flyfrontier.com before travel. BagRule is not affiliated with Frontier Airlines.