Britax Poplar Convertible Car Seat

6% off$329.99List price $349.99

Price on Amazon.com as of 2026-11-02 09:10 UTC, and subject to change.

A convertible car seat with 2 modes: rear-facing harness 5 to 50 lb, 18 to 49 in; forward-facing harness 30 to 65 lb, 35 to 49 in.

At a glance

  • Fits children from 5 to 65 lb
  • Up to 49 in tall
  • 2 modes: rear-facing harness, forward-facing harness
  • Seat weighs 27.2 lb
  • 17 in wide
  • 10-year usable life
  • Certified for aircraft use
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Specifications checked against Britax’s US site and manual on . Not hands-on tested. How I research

Who is the Poplar Convertible Car Seat for?

The Britax Poplar is a convertible car seat in a slim 17 inch design. The manual allows rear-facing from 5 to 50 lb and 18 to 49 inches, and forward-facing from 30 to 65 lb and 35 to 49 inches. It installs with ClickTight, is certified for aircraft in both directions, and expires after 10 years.

Reasons to consider it

  • A lap-shoulder belt install with ClickTight, without locking the retractor
  • A 14-position harness and headrest that adjust together without rethreading
  • Aircraft certification, rear- and forward-facing
  • A tether whose colored stitching shows when the seat has been in a crash and must be replaced

Things to weigh up

  • Lower anchors are limited to 35 lb, rear- and forward-facing
  • The manual says not to use the tether rear-facing
  • Britax lists the seat at 27.2 lb
  • Britax does not list a stability bar for this model; the Poplar S includes one

My take on the Poplar Convertible Car Seat

The Poplar suits a family that needs a narrow convertible for a crowded back seat and wants one seat from 5 lb rear-facing to the 65 lb forward-facing limit. The main trade-off is bulk to move: Britax lists it at 27.2 lb. The Poplar S shares its limits and 17 inch width but adds a ReboundReduce stability bar for rear-facing use and a second infant insert, and Britax lists it at 28.0 lb.

A research summary of Britax’s published specifications and manual, read . Not a hands-on test or a crash-safety rating.

Who the Poplar Convertible Car Seat fits

This seat covers 2 stages, and a child has to meet every limit of the stage they are in. Britax gives it a 10-year life from the date of manufacture, so check the date label before using a hand-me-down.

Rear-facing harness5 to 50 lb · 18 to 49 in
The child faces the back of the car, which keeps the head, neck and spine supported in a frontal crash. Keep this mode as long as the child fits it.
Forward-facing harness30 to 65 lb · 35 to 49 in
The child faces forward in the seat’s own harness. Use the top tether every time, and stay in the harness until the child outgrows it.

What are the Poplar Convertible Car Seat weight, height and age limits?

Britax Poplar Convertible Car Seat limits by mode
ModeChild weightChild heightMinimum ageConditions
Rear-facing harness5 to 50 lb18 to 49 inNot publishedLower anchor installation limited to 35 lb (manual)
Forward-facing harness30 to 65 lb35 to 49 inNot publishedLower anchor installation limited to 35 lb (manual)

A child must meet every limit for the mode they use. The labels on your seat and its manual are the final word.

Poplar Convertible Car Seat specifications

Seat weight
27.2 lb
Width
17 in
Usable life
10 years
Aircraft use
Certified for aircraft (see manual for which modes)
Dimensions
20.5" x 17" x 23.5"
Harness positions
14
Recline positions
6
Buckle strap depths
4, 7 in
Seat area depth
11 in
Seat area width
12 in
Shoulder width
14 in
Harness slot heights
8, 8.7, 9.4, 10.1, 10.8, 11.5, 12.2, 12.9, 13.6, 14.3, 15, 15.7, 16.4, 17 in

How the Poplar Convertible Car Seat installs

Belt lock-off
ClickTight installation. A lock-off clamps the vehicle belt so you do not have to switch the belt's retractor into its locked mode.
Recline
6 recline positions. The recline angle is what keeps a young baby’s airway open, so set it before tightening the install.
Harness
14-position no-rethread harness and headrest. Check the harness height at each growth spurt: at or below the shoulders rear-facing, at or above them forward-facing.

Every install is a fit between one seat and one vehicle. Read both manuals, and use a free inspection station if anything is unclear.

An empty car seat installed on a back seat, seen through an open car door

Will it fit your car?

At 17 in at its widest, this seat is one of the narrower ones in its class and is a candidate for three across in many mid-size cars. It weighs 27.2 lb, which matters if you will move it between cars or carry it through an airport.

  • Check your vehicle manual for lower anchor positions and any head-restraint rules.
  • Rear-facing seats need front-seat room: try the install behind the driver before you commit.
  • Certified for aircraft use, so it can travel as a seat rather than checked baggage.

What features does the Poplar Convertible Car Seat have?

  • ClickTight installation
  • 14-position no-rethread harness and headrest
  • 6 recline positions
  • V-shaped tether
  • SafeCell technology
  • Carbon steel frame

Colors listed in the US

Stone Onyx, Glacier Graphite.

Poplar Convertible Car Seat colors and prices

2 colors are listed on Amazon right now. Prices differ by color, so compare before choosing. The fabric is the only difference between them; the shell, harness and limits are identical. Prices were retrieved Nov 2, 9:10 AM UTC and can change.

Compare Poplar Convertible Car Seat colors side by side
Compare colorsGlacier Graphite 2.0Check priceStone Onyx 2.0Check price
Price6% off$329.99List price $349.99$349.99
AvailabilityIn stockIn stock
Price checkedNov 2, 9:10 AM UTCNov 2, 9:14 AM UTC

Prices and availability shown are accurate as of the time indicated and are subject to change. Any price and availability information displayed on Amazon.com at the time of purchase will apply. As an Amazon Associate I earn from qualifying purchases.

What to know before you live with it

Installing it rear-facing

You set the recline before installing: rear-facing, the indicator ball must be completely in the blue section, and Britax recommends the most reclined position for a baby without head and neck control. A rolled towel or pool noodle is allowed if needed. The base must be flat and parallel on the vehicle seat with no more than 3 inches over the front edge. To install, you lift the front cover flap, squeeze the ClickTight release buttons, slide both parts of the belt through the rear-facing belt paths, buckle, remove slack from the lap and then the shoulder part, and close the ClickTight. The tether stays attached to its storage hook.

Source: Britax Poplar user guide P15154500 (PDF)

Forward-facing and the tether

Forward-facing, the recline indicator ball must sit within the dashed green lines, and Britax strongly recommends using the tether. The manual describes the tether as a crash indicator: if any of its colored stitching has ripped, the seat is no longer acceptable for use. It also warns that a vehicle head restraint can stop the seat's head restraint from rising high enough in a reclined forward-facing position. In that case you raise or remove the vehicle head restraint, or move the seat upright or to another seating position, and never force it.

Source: Britax Poplar user guide P15154500 (PDF)

Positioning layer and infant insert

A positioning layer sits under the child and changes with weight. Rear-facing, it must be folded down from 5 to 40 lb and may be up or down from 40 to 50 lb. Forward-facing, it must be folded down from 30 to 40 lb and may be up or down from 40 to 65 lb. When folded up, it goes behind the head restraint bib. The lower infant insert sits on top of the positioning layer, may be used for children of 20 lb or less rear-facing, and is never used forward-facing.

Source: Britax Poplar user guide P15154500 (PDF)

Cover, cup holders and cleaning

The cover comes off in three parts: a head restraint cover, a seat pan cover and an outer rim cover, each with its own steps in the manual. For washing, it points you to the care label and says not to bleach or iron. The shell and harness are sponge cleaned with warm water and mild soap, and the harness is never taken apart. The buckle is rinsed in warm water and tested until each tongue clicks. The two cup holders are removable and dishwasher safe, and either the cup holders or the cup holder caps must always be in place.

Source: Britax Poplar user guide P15154500 (PDF)

Is the Poplar Convertible Car Seat recalled?

No campaign in the current NHTSA child-restraint data names this model family, and I have not run a separate review for it. Check your seat’s model number and date of manufacture before use.

NHTSA recall search · Recent car seat recalls

Poplar Convertible Car Seat: common questions

What are the Britax Poplar weight and height limits?

The manual allows rear-facing from 5 to 50 lb and 18 to 49 inches, and forward-facing from 30 to 65 lb and 35 to 49 inches. Rear-facing, the head must be at least 1 inch below the top of the head restraint; forward-facing, the tops of the ears must be below it.

Britax Poplar user guide P15154500 (PDF) (opens in a new tab)

Is the Poplar FAA approved for airplanes?

The manual says it is certified for use in motor vehicles and aircraft. Rear-facing, the aircraft lap belt goes through the rear-facing belt paths; forward-facing, the seat is upright and the belt goes through the forward-facing paths.

Britax Poplar user guide P15154500 (PDF) (opens in a new tab)

What is the Poplar LATCH weight limit?

The manual says not to use the lower anchor attachment for a child over 35 lb, rear-facing or forward-facing. Above that, you install with the vehicle belt.

Britax Poplar user guide P15154500 (PDF) (opens in a new tab)

How heavy and how wide is the Poplar?

Britax lists the seat at 27.2 lb, gives dimensions of 20.5 x 17 x 23.5 inches and calls it a slim 17 inch design. It says the seat is designed to fit 3 across but that fit cannot be guaranteed in all vehicles.

Britax Poplar Convertible Car Seat product page (opens in a new tab)

What is the difference between the Poplar and the Poplar S?

Britax lists the Poplar S with the same 50 lb rear-facing and 65 lb forward-facing limits, a ReboundReduce stability bar for rear-facing use, two infant inserts and a 28.0 lb seat weight.

Britax Poplar S Convertible Car Seat product page (opens in a new tab)

When does the Poplar expire?

The manual says to stop using it once it is older than ten years, or after a moderate or severe crash. The date is on the serial number and manufactured date label.

Britax Poplar user guide P15154500 (PDF) (opens in a new tab)

Answers refer to the model and manual version on this page. Check the instructions supplied with your seat.

Before you buy

  1. Weigh and measure your child. The limits above are the manufacturer’s, and a child has to meet all of them for the mode they will use.
  2. Confirm the exact version. Colors, retail exclusives and model numbers change limits more often than you would expect; Britax lists 2 colors of this seat.
  3. Read the manual before you buy, not after. It is linked above and holds the fit rules, the install methods and the expiry.
  4. Check recalls by model number and date of manufacture, and register the seat with Britax so you hear about the next one.

Sources

Other Britax convertible car seats

ModelTop child weightSeat weightWidthUsable life
Poplar Convertible Car Seat (this seat)65 lb27.2 lb17 in10 years
Poplar S Convertible Car Seat65 lb28 lb17 in10 years
One4Life ClickTight All-in-One Car Seat120 lb30 lb19.5 in10 years
One4Life Slim All-in-One Car Seat120 lb28 lb—10 years