Toyota Yaris Back Up Light Bulb Size

The Toyota Yaris back up light requires a 921 bulb size for proper installation and function within the rear lighting assembly. Data for the bulb specifications covers the range from 2013 to 2019.

The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.

Back Up Light

Years	US Type	EU Type	Shop
2018-2019	921	W16W	Check Price
2013-2014	921	W16W	Check Price

Outer Back Up Light

If US Type and EU Type show the same value, a direct cross-reference for this bulb is not available or the data is insufficient.

Years	US Type	EU Type	Shop
2018-2019	921	W16W	Check Price
2014	921	W16W	Check Price
2013	3057	3057	Check Price

Bulb Specifications

Description	Type	Shop
ANSI standard (US & Canada). Wedge bulb (T15). 12V, 16W.	921	Check Price
ANSI standard (US & Canada). Dual-filament wedge bulb (T25). 12V, 27W/7W.	3057	Check Price

Other Locations

Additional Notes

The 921 bulb is an ANSI-standard wedge type in the T15 form factor, rated at 12 volts and 16 watts, and it serves as the back up light bulb across the Toyota Yaris for the 2013-2014 and 2018-2019 model years.
The T15 designation refers to the bulb's tubular glass envelope, with the number indicating its width in eighths of an inch, and the wedge base design means the bulb is held in place by friction rather than a bayonet or screw mechanism.
The 3057 bulb is a dual-filament wedge type in the T25 form factor, rated at 12 volts with a 27-watt primary filament and a 7-watt secondary filament, and it appears in the outer back up light position of the 2013 Toyota Yaris.
Because the 3057 carries two filaments, it is electrically and functionally distinct from the single-filament 921, and the two bulb types are not interchangeable despite both using wedge bases.
The outer back up light position on the 2013 Toyota Yaris uses the 3057, while the same position on the 2014, 2018, and 2019 model years uses the 921, indicating a specification change between those model years.
Both the 921 and 3057 conform to ANSI standards applicable in the United States and Canada, meaning their electrical and physical specifications follow a defined industry classification system.