How do I know my headlight bulb size?
The quickest way to know your headlight bulb size is to check your vehicle’s owner’s manual or inspect the current bulb for its size code, and then verify with an online parts catalog using your car’s make, model, year, or VIN.
Bulb size refers to the base type and connector standard, not the wattage, and different lighting configurations (halogen, HID, LED) require different replacements. This guide explains practical steps to determine the correct bulb size and what to watch out for on newer vehicles.
Identify the bulb size: practical methods
These methods are the most reliable for confirming the exact bulb type your car needs. Use one or a combination to ensure accuracy before purchasing.
- Check the owner’s manual or a factory service manual for the exact bulb size code used by your model.
- Remove the headlight bulb and read the markings on the base or glass of the bulb (common codes include H11, 9005, H7, etc.).
- Use your vehicle’s make, model, and year, or enter the VIN in a reputable online parts catalog or the dealership’s parts site to look up the correct bulb size.
- Cross-check with a retailer’s fitment tool by entering your car details and compare the listed size to the bulb you plan to buy. If in doubt, contact a parts specialist for confirmation.
Concluding: By using the manual, inspecting the bulb itself, and/or validating through a trusted parts database, you’ll identify the correct bulb size and reduce the risk of purchasing the wrong part.
Common headlight bulb sizes you may encounter
Here is a quick reference of sizes you’ll typically see in catalogs. Note that size codes refer to the bulb base, and some cars use HID or LED modules rather than loose halogen bulbs. Always verify with your vehicle’s documentation.
- H1 – a single-beam halogen often used for high-beam or projector setups
- H4 (HB2) – a dual-filament halogen used in many older European and some Asian vehicles
- H7 – a very common low-beam bulb in modern vehicles
- H11 – widely used for low-beam and some fog lights
- 9005 (HB3) – commonly used for high-beam applications
- 9006 (HB4) – used in some low-beam or fog light configurations
- 9004 (HB1) – found on older models with dual-filament setups
- 9012 – used on certain mid-size and SUV models for specific high/low-beam or fog light roles
- H13 – a round, dual-filament bulb used in some trucks and SUVs
Note: For vehicles with HID or LED headlights, the “bulb size” may refer to a ballast/driver type or an integrated module (e.g., D1S, D2S, D3S, D4S for HID). Confirm compatibility before purchasing replacement modules or bulbs.
Special cases and installation tips
Modern vehicles sometimes use non-replaceable LED assemblies or HID systems that require specific ballasts or drivers. If you’re replacing a whole assembly or a module, you may need to consider alignment, wiring, and calibration procedures recommended by the manufacturer.
When handling halogen bulbs, wear clean gloves or use a cloth, since oils from skin can shorten bulb life or cause hot spots. After replacing bulbs, test the headlights and have them aimed correctly at night to ensure optimal visibility and to avoid glare for oncoming drivers.
Summary
To know your headlight bulb size, consult the owner’s manual, inspect the current bulb for size markings, and verify with an online parts catalog or dealer by using your vehicle’s make/model/year or VIN. Remember that modern vehicles may use HID or LED assemblies, where the relevant specification is the base/MODULE type rather than a simple halogen size. Always confirm before purchasing and handle bulbs safely during replacement.
