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Knack Bags

Series 2 Large Expandable Backpack

Likely carry-on-only. | Official Knack page shows 30L unexpanded, 46L expanded, 21.5 x 14 x 4.5 in, and 3 lb 4 oz. | Launch-only softness, compressibility, opening, bottle-pocket, and price fields inferred from category and model.

Dimensions
21.5 x 14 x 4.5 in
Capacity
30 L
Weight
3.25 lb
Last reviewed
2026-05-29
Audited dimensions

Bag data

Audited dimensions
Last reviewed
2026-05-29
Dimension confidence
high
Primary source
manufacturer

Fit by airline

Airline fit results

Carry-on

Knack Bags Series 2 Large Expandable Backpack

Fits

Knack Bags Series 2 Large Expandable Backpack fits the published carry-on dimensions for this rule. Still measure the packed bag, including handles and wheels.

Visual sizer

Bag vs airline rule

Fits

Fits. Tightest spare room: 0.2 in.

Dimension-only silhouette
Scaled fit visualizationFits. Tightest spare room: 0.2 in.Bag size21.5 x 14 x 4.5 inRule size21.7 x 15.7 x 7.9 inRule width 15.7 inRule length 21.7 inBag width 14 inBag length 21.5 inDepth: Bag 4.5 in / Rule 7.9 in

Fits. Tightest spare room: 0.2 in.

Height

Spare room +0.2 in

Bag 21.5 in / Rule 21.7 in

Width

Spare room +1.7 in

Bag 14 in / Rule 15.7 in

Depth

Spare room +3.4 in

Bag 4.5 in / Rule 7.9 in

  • warning: This result uses medium-confidence source data.

Data status

Audited dimensionsSource-linked rule

Rendered from the dimensions shown here. Airline staff and packed shape can still affect the real-world outcome.

Dimension-only silhouette rendered from verified dimensions; no approved product image is available yet.

Bag
21.5 x 14 x 4.5 in
Rule
21.7 x 15.7 x 7.9 in
Risk
8/100
Confidence
medium

Margins: length 0.2 in, width 1.7 in, depth 3.4 in.

Personal item

Knack Bags Series 2 Large Expandable Backpack

Does not fit

Knack Bags Series 2 Large Expandable Backpack is larger than the published personal-item dimensions. Pick a smaller alternative for this airline rule.

Bag
21.5 x 14 x 4.5 in
Rule
13 x 9.8 x 7.9 in
Risk
92/100
Confidence
medium

Margins: length -8.5 in, width -4.2 in, depth 3.4 in.

Main issue: length by 8.5 in, width by 4.2 in.

Carry-on

Knack Bags Series 2 Large Expandable Backpack

Risky

Knack Bags Series 2 Large Expandable Backpack is over the published carry-on dimensions, but the soft construction may make it a borderline option if lightly packed. Treat this as a fee-risk result.

Bag
21.5 x 14 x 4.5 in
Rule
21.7 x 13.8 x 9.8 in
Risk
48/100
Confidence
medium

Margins: length 0.2 in, width -0.2 in, depth 5.3 in.

Main issue: width by 0.2 in.

Personal item

Knack Bags Series 2 Large Expandable Backpack

Does not fit

Knack Bags Series 2 Large Expandable Backpack is larger than the published personal-item dimensions. Pick a smaller alternative for this airline rule.

Bag
21.5 x 14 x 4.5 in
Rule
17.7 x 13.8 x 7.9 in
Risk
92/100
Confidence
medium

Margins: length -3.8 in, width -0.2 in, depth 3.4 in.

Main issue: length by 3.8 in, width by 0.2 in.

Carry-on

Knack Bags Series 2 Large Expandable Backpack

Fits

Knack Bags Series 2 Large Expandable Backpack fits the published carry-on dimensions for this rule. Still measure the packed bag, including handles and wheels.

Bag
21.5 x 14 x 4.5 in
Rule
21.7 x 15.7 x 9.1 in
Risk
8/100
Confidence
medium

Margins: length 0.2 in, width 1.7 in, depth 4.6 in.

Carry-on

Knack Bags Series 2 Large Expandable Backpack

Fits

Knack Bags Series 2 Large Expandable Backpack fits the published carry-on dimensions for this rule. Still measure the packed bag, including handles and wheels.

Bag
21.5 x 14 x 4.5 in
Rule
21.7 x 15.7 x 9.1 in
Risk
8/100
Confidence
medium

Margins: length 0.2 in, width 1.7 in, depth 4.6 in.

Carry-on

Knack Bags Series 2 Large Expandable Backpack

Fits

Knack Bags Series 2 Large Expandable Backpack fits the published carry-on dimensions for this rule. Still measure the packed bag, including handles and wheels.

Bag
21.5 x 14 x 4.5 in
Rule
21.7 x 15.7 x 9.1 in
Risk
8/100
Confidence
medium

Margins: length 0.2 in, width 1.7 in, depth 4.6 in.

Carry-on

Knack Bags Series 2 Large Expandable Backpack

Fits

Knack Bags Series 2 Large Expandable Backpack fits the published carry-on dimensions for this rule. Still measure the packed bag, including handles and wheels.

Bag
21.5 x 14 x 4.5 in
Rule
21.7 x 15.7 x 9.1 in
Risk
8/100
Confidence
medium

Margins: length 0.2 in, width 1.7 in, depth 4.6 in.