Knox › fit in › Subaru Crosstrek

Will the UPPAbaby Knox fit in a 2018–2024 Subaru Crosstrek?

Yes — the UPPAbaby Knox fits a 2018–2024 Subaru Crosstrek, with a caveat.
The Knox is about 18.8" wide; the Crosstrek's usable rear bench is about 49". It fits one rear position comfortably. Three across is tight (56.4" needed vs 49"). Note: rear legroom here is limited, so a rear-facing install may crowd the front passenger.

18.8"Knox width

49"Crosstrek rear bench

Tightthree across

★★★☆☆NHTSA Ease-of-Use

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What fits this Crosstrek

One seat, rear position: Yes. The Knox installs in an outboard rear position of a 2018–2024 Subaru Crosstrek, though you may slide the front seat forward for rear-facing.
Three across: Tight — three need ~56.4" against only ~49". A narrower seat is the better bet.
Modes this seat covers: rear-facing → forward-facing.
LATCH: lower anchors up to 35 lb; the Crosstrek has 2 lower-anchor positions.

ℹ️ Informational only — built from NHTSA public car-seat ratings and published seat/vehicle dimensions. This is not a safety certification and not a substitute for the seat and vehicle manuals. Always confirm the fit and install yourself before every trip. The Knox's width (UPPAbaby published spec (23.8"L x 18.8"W x 27.4-32.5"H); independent review measured 18.6 in, closely matching) and the Crosstrek's rear-bench width (Subaru dimensions + owner measurements (approx); compact crossover, shorter rear legroom) are both approximate — confirm with a test-fit before buying.

Common questions

Will the UPPAbaby Knox fit in a 2018–2024 Subaru Crosstrek?

Yes — the UPPAbaby Knox (18.8" wide) fits a single rear seating position in a 2018–2024 Subaru Crosstrek. Because this vehicle has limited rear legroom, a rear-facing install may require sliding the front seat forward. Three across is tight — its rear bench is about 49" and three of these would need 56.4".

Can you fit three Knoxs across a Crosstrek?

Probably not — three Knoxs need about 56.4" but the Crosstrek's usable bench is only about 49". Consider a narrower seat — see our narrowest-seats guide.

Sources: seat ratings & modes — NHTSA (pulled 2026-10-13); dimensions — manufacturer specs and owner measurements. Informational only — built from NHTSA public car-seat ratings and published seat/vehicle dimensions. This is not a safety certification and not a substitute for the seat and vehicle manuals. Always confirm the fit and install yourself before every trip.