Used for: Back Up Reverse Light Bulb
Used for: Parking Light Bulb, Turn Signal Light Bulb Front
Used for: Side Marker Light Bulb Front
Used for: Turn Signal Light Bulb Rear
Used for: Interior Door Light Bulb, Trunk or Cargo Area Light
This 2021 Lexus RX 350 bulb size guide helps you verify the correct replacement bulb by lighting position, so you can match the right part to the right lamp. Whether you are replacing an exterior signal light or an interior convenience light, checking the bulb chart by location is the easiest way to avoid ordering the wrong item.
On the 2021 Lexus RX 350, many exterior and interior lights use LED assemblies, while a few positions may still use replaceable bulbs such as 7444NA, 7440A, 921, 168NA, or 168 depending on the lamp. Because trim level, market, and lighting package can affect fitment, this page is meant to help you narrow down the correct bulb size before you buy.
For best results, compare the bulb position on your vehicle with the chart and confirm what is actually installed before purchasing. Some 2021 RX 350 models use factory LED units that are not serviced with a simple bulb swap, while others may share the same housing across trims but differ in the internal light source or connector style. If you are considering an aftermarket LED conversion for a halogen-style socket, make sure the bulb base, polarity, and physical clearance are compatible with the housing, and always verify the original bulb number on the removed part when possible.
The chart lists the headlight high beam and low beam as LED on the 2021 Lexus RX 350. In many cases, that means the headlamp is an LED assembly rather than a standard replaceable bulb.
The front fog light is listed as LED. If your vehicle has factory LED fog lights, the light source may be integrated into the assembly instead of being a separate bulb.
The front turn signal light bulb is listed as 7444NA on the 2021 Lexus RX 350.
The rear turn signal light bulb is listed as 7440A.
The back-up reverse light bulb is listed as 921 for the 2021 RX 350.
The license plate light is listed as LED. That usually indicates a factory LED lamp or module rather than a standard replaceable incandescent bulb.
Both the brake light bulb and the center high mount stop light bulb are listed as LED on this vehicle.
The front side marker light bulb is listed as 168NA.
The rear side marker light is listed as LED.
The parking light bulb is listed as 7444NA, with an optional note on some configurations. Always confirm the installed setup before ordering.
The dome light, map light, and glove box light are listed as LED, while the trunk or cargo area light is listed as 168. The interior door light is also listed as 168.
Trim and lighting package can vary by market and body style, and that can change whether a lamp uses a replaceable bulb or an LED module. Checking your exact vehicle configuration helps prevent fitment mistakes.
