SeatFitFindercar seats, by spec

FAA-approved convertible car seats

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Convertible seats that carry the faa-approved spec — 22 models to shortlist from.

Short answer: Going by each maker's manual, the highest rear-facing limit here is 50 lb (8 of the 22 seats). The forward-facing harness goes up to 65 lb, and high-back booster mode up to 120 lb on the 8 seats that have it. Useful life is 7 to 10 years where the manual gives one.

Fit is decided by your seat manual + your vehicle manual. This page lists published specs to help you shortlist — it is not installation or safety advice, and it does not confirm a seat fits a specific car. Confirm install with the manuals, NHTSA, or a free certified car-seat technician (CPST) check.

Last verified 2026-06-11 · 22 models

Car seatStageNarrow (3-across)Ext. rear-facingFAALightweightBuy
Graco Extend2FitConvertible4–65 lbNHTSA notice 2016Convertible–✓✓–See price
on Amazon
Chicco NextFit MaxConvertible4–65 lbConvertible–✓✓–See price
on Amazon
Britax Marathon ClickTightConvertible5–65 lbNHTSA notice 2015Convertible––✓–See price
on Amazon
Britax Boulevard ClickTightConvertible5–65 lbNHTSA notice 2015Convertible––✓–See price
on Amazon
Nuna RAVAConvertible5–65 lbNHTSA notice 2024Convertible–✓✓–See price
on Amazon
Clek FlloConvertible14–65 lbNHTSA notice 2021Convertible✓✓✓–See price
on Amazon
Diono Radian 3QXTConvertible4–120 lbConvertible✓✓✓–See price
on Amazon
Diono Radian 3RXTConvertible5–120 lbConvertible✓✓✓–See price
on Amazon
Cosco Scenera NEXTConvertible5–40 lbConvertible✓–✓✓See price
on Amazon
WAYB PicoConvertible26.5–50 lbNHTSA notice 2019Convertible✓–✓✓See price
on Amazon
Evenflo Tribute LXConvertible5–40 lbConvertible✓–✓✓See price
on Amazon
Graco Contender SlimConvertible5–65 lbConvertible✓–✓–See price
on Amazon
Graco SlimFit3 LXConvertible5–100 lbConvertible✓–✓–See price
on Amazon
Britax Advocate ClickTightConvertible5–65 lbNHTSA notice 2015Convertible––✓–See price
on Amazon
Britax AllegianceConvertible5–65 lbConvertible––✓–See price
on Amazon
Maxi-Cosi Pria MaxConvertible4–100 lbConvertible––✓–See price
on Amazon
Chicco OneFit ClearTexConvertible5–100 lbConvertible––✓–See price
on Amazon
Safety 1st Grow and Go SprintConvertible5–100 lbConvertible––✓–See price
on Amazon
Chicco NextFit ZipConvertible5–65 lbConvertible–✓✓–See price
on Amazon
Diono Radian 3RConvertible5–120 lbConvertible✓–✓–See price
on Amazon
Graco Sequel 65Convertible4–65 lbConvertible–✓✓–See price
on Amazon
Cybex Eternis SConvertible4–120 lbConvertible–✓✓–See price
on Amazon

Harnessed seats are FAA-approved for aircraft; boosters are not (a plane seat has no shoulder belt).

Weight limits and useful life, seat by seat

The weight ranges each maker prints in the seat's manual. Tap a seat to see it side by side with a similar model, with height limits and a link to its manual.

Car seatRear-facingForward-facing harnessHigh-back boosterUseful life
Graco Extend2Fit4–50 lb22–65 lb—10 yrs
Chicco NextFit Max4–50 lb22–65 lb—8 yrs
Britax Marathon ClickTight5–40 lb22–65 lb—10 yrs
Britax Boulevard ClickTight5–40 lb22–65 lb—10 yrs
Nuna RAVA5–50 lb25–65 lb—10 yrs
Clek Fllo14–50 lb26.5–65 lb—9 yrs
Diono Radian 3QXT4–50 lb22–65 lb40–120 lb10 yrs from purchase
Diono Radian 3RXT5–50 lb22–65 lb40–120 lb10 yrs from purchase
Cosco Scenera NEXT5–40 lb22–40 lb—8 yrs
WAYB Pico—26.5–50 lb—7 yrs
Evenflo Tribute LX5–40 lb22–40 lb——
Graco Contender Slim5–40 lb20–65 lb—7 yrs
Graco SlimFit3 LX5–40 lb22–65 lb40–100 lb10 yrs
Britax Advocate ClickTight5–40 lb22–65 lb—10 yrs
Britax Allegiance5–40 lb20–65 lb—7 yrs
Maxi-Cosi Pria Max4–40 lb22–65 lb40–100 lb10 yrs
Chicco OneFit ClearTex5–40 lb25–65 lb40–100 lb10 yrs
Safety 1st Grow and Go Sprint5–40 lb30–65 lb40–100 lb10 yrs
Chicco NextFit Zip5–40 lb22–65 lb—8 yrs
Diono Radian 3R5–50 lb26.5–65 lb40–120 lb10 yrs from purchase
Graco Sequel 654–40 lb22–65 lb—10 yrs
Cybex Eternis S4–50 lb22–65 lb40–120 lb—

“—” means the manual we cite gives no figure for that mode. Useful life counts from the date of manufacture unless it says “from purchase”. How these are sourced

Common questions

Which FAA-approved convertible car seats have the highest rear-facing weight limit?

The Graco Extend2Fit, the Chicco NextFit Max, the Nuna RAVA, the Clek Fllo, the Diono Radian 3QXT, the Diono Radian 3RXT, the Diono Radian 3R and the Cybex Eternis S list a rear-facing limit of 50 lb, the highest here. The lowest is 40 lb (the Britax Marathon ClickTight, the Britax Boulevard ClickTight, the Cosco Scenera NEXT and 10 more). These are the makers' printed limits; your child's height also has to fit.

How heavy can a child be in the forward-facing harness?

Between 40 lb and 65 lb, depending on the seat. 19 of the 22 seats here with a forward-facing harness go up to 65 lb.

Up to what weight can these be used as a booster?

In high-back booster mode the maximum is between 100 and 120 lb; the Diono Radian 3QXT, the Diono Radian 3RXT, the Diono Radian 3R and the Cybex Eternis S go to 120 lb. A booster also needs the seat belt to fit your child, so check the height range in the manual too.

How long do FAA-approved convertible car seats last before they expire?

The manuals list a useful life of 7 to 10 years. Most count from the date of manufacture; the Diono Radian 3QXT, the Diono Radian 3RXT and the Diono Radian 3R count from the date of purchase. For 2 of the 22, the manual we cite gives no figure, so check the label on the seat. More by brand on car seat expiration.

Which of these FAA-approved convertible car seats are narrow enough for 3-across?

9 of the 22 are made narrow for fitting three across: the Clek Fllo, the Diono Radian 3QXT, the Diono Radian 3RXT, the Cosco Scenera NEXT, the WAYB Pico, the Evenflo Tribute LX, the Graco Contender Slim, the Graco SlimFit3 LX and the Diono Radian 3R. Whether three fit depends on your back seat, so test-fit in your car.

More: all convertible seats · all faa-approved seats · how to check fit →