MightyFit 65 › fit in › Kia Rio

Will the Cosco MightyFit 65 fit in a 2018–2023 Kia Rio?

Yes — the Cosco MightyFit 65 fits a 2018–2023 Kia Rio, with a caveat.
The MightyFit 65 is about 18" wide; the Rio's usable rear bench is about 47". It fits one rear position comfortably. Three across is tight (54" needed vs 47"). Note: rear legroom here is limited, so a rear-facing install may crowd the front passenger.

18"MightyFit 65 width

47"Rio rear bench

Tightthree across

★★★☆☆NHTSA Ease-of-Use

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What fits this Rio

One seat, rear position: Yes. The MightyFit 65 installs in an outboard rear position of a 2018–2023 Kia Rio, though you may slide the front seat forward for rear-facing.
Three across: Tight — three need ~54" against only ~47". A narrower seat is the better bet.
Modes this seat covers: rear-facing → forward-facing.
LATCH: lower anchors up to 55 lb; the Rio 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 MightyFit 65's width (Cosco published spec (~18 in)) and the Rio's rear-bench width (Typical for subcompact car — approximate, verify install in your vehicle) are both approximate — confirm with a test-fit before buying.

Common questions

Will the Cosco MightyFit 65 fit in a 2018–2023 Kia Rio?

Yes — the Cosco MightyFit 65 (18" wide) fits a single rear seating position in a 2018–2023 Kia Rio. 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 47" and three of these would need 54".

Can you fit three MightyFit 65s across a Rio?

Probably not — three MightyFit 65s need about 54" but the Rio's usable bench is only about 47". Consider a narrower seat — see our narrowest-seats guide.

Sources: seat ratings & modes — NHTSA (pulled 2026-06-18); 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.