Adjust headlights by turning screws on the back of the headlight housing, one for vertical aim and one for horizontal aim
Most headlights can be adjusted without special tools or a trip to a mechanic. The adjustment screws sit on the back or side of the headlight assembly — typically two screws per light, one that moves the beam up and down, and one that moves it left and right. You can do this in your driveway in 10 to 20 minutes, though the exact location and number of screws varies by vehicle make and model.
Misaligned headlights are a safety issue and a legal one. Lights aimed too high blind oncoming drivers. Lights aimed too low reduce your own visibility and may fail a vehicle inspection. Many states have inspection stations that will check alignment as part of their annual or biennial safety test, and some will flag misalignment as a reason to fail.
Key Takeaways
- Headlight adjustment screws are located on the back or side of the headlight housing and are usually labeled with arrows or plus and minus symbols.
- You need a level surface, a wall or garage door to project the beam onto, and a screwdriver that fits the adjustment screws — typically Phillips or flathead.
- Aim the low beam so the brightest spot hits the wall at or slightly below the height of your headlights, about 25 feet away.
- If you cannot locate the screws or your vehicle has sealed headlight units, a mechanic or alignment shop can adjust them, usually for $20 to $50 per vehicle.
What you need before you start
Park on a level surface — a driveway or parking lot, not a slope — with the front of your car about 25 feet from a wall, garage door, or other flat vertical surface. The car should be at normal operating weight: you in the driver's seat, a full tank of gas, and normal cargo. Do not load the trunk with extra weight or remove passengers, because the suspension height affects beam angle.
Gather a screwdriver (Phillips or flathead, depending on your vehicle), a flashlight or work light, and your vehicle's owner's manual or a quick online search for your make, model, and year. The manual will show you exactly where the adjustment screws are and which direction each one turns. If you cannot find the manual, search "[your year, make, model] headlight adjustment" — most manufacturers publish this information online.
Turn on your low beams and let your eyes adjust to the dark for a minute or two. High beams are not adjusted the same way and should not be used for this task.
Locating and identifying the adjustment screws
Open the hood and look at the back of the headlight housing. You will see two screws, usually with arrows or plus and minus symbols printed or molded nearby. One screw controls vertical aim (up and down), and one controls horizontal aim (left and right). The vertical screw is often on top or on the inner edge of the housing; the horizontal screw is often on the side or bottom.
Some vehicles have the screws accessible from inside the engine bay. Others require you to remove a trim panel or reach from underneath. If the screws are not when ready visible, check your owner's manual or search for a diagram specific to your vehicle. Sealed headlight units — common on newer cars — often cannot be adjusted by the owner and require a mechanic or dealership.
Do not confuse focus adjustment (which sharpens the beam) with aim adjustment (which moves the beam up, down, left, or right). Focus screws are usually smaller and located deeper in the housing. Aim screws are the larger, more accessible ones.
Aiming the low beam correctly
Stand in front of your car, about 25 feet away, facing the wall. Look at where the low beam hits the wall. The brightest spot of the beam should be at or slightly below the height of your headlights — roughly at the center of the wall at that distance. The beam should not be so high that it creates a bright spot above the midline, and it should not be so low that the wall is dark at headlight height.
If the beam is too high, turn the vertical adjustment screw (usually clockwise) to lower it. If it is too low, turn it counterclockwise to raise it. Make small adjustments — a quarter turn at a time — and check the wall after each one. The beam will move noticeably with even a small turn.
Once the vertical aim is correct, check the horizontal aim. The beam should be centered on the wall, not drifting to the left or right. If it is off-center, turn the horizontal adjustment screw to move it. Again, small adjustments are better than large ones.
Adjusting both headlights to match
Repeat the process for the other headlight. Both beams should hit the wall at the same height and in the same horizontal position. If one is noticeably higher or lower than the other, the beams are not aligned with each other, and oncoming drivers will see an uneven pattern.
Some vehicles have a third screw or lever that adjusts both headlights together, useful if both are off by the same amount. Check your manual to see if your car has this feature. If it does, use it to make a gross adjustment first, then fine-tune each light individually.
Step back and look at the overall pattern. The beams should form a symmetrical V shape on the wall, with the brightest spots at roughly the same height and distance from center.
When to use high beams and why they are not adjusted the same way
High beams are designed to point straight ahead and slightly upward, and they are not adjusted by the owner in most vehicles. They are controlled by a lever or button inside the car, not by screws on the housing. If your high beams seem misaligned, the issue is usually a burned-out bulb or a problem with the reflector inside the housing, not the aim.
Some older vehicles do have high beam adjustment screws, but they are less common. Check your manual before attempting to adjust them. High beams that are too low are useless; high beams that are too high are dangerous and illegal in most places.
What to do if you cannot find or access the screws
Modern vehicles, especially those with LED or HID headlights, often have sealed units that cannot be adjusted without removing the entire assembly. If you cannot locate adjustment screws after checking your manual and the back of the housing, your car likely falls into this category.
A mechanic, dealership, or alignment shop can adjust sealed headlights using specialized equipment. The cost is typically $20 to $50 per vehicle, sometimes included as part of a larger alignment service. Some shops will do it while you wait; others may need to schedule an appointment.
Frequently Asked Questions
How often should I check my headlight aim?
Check it once a year or after any collision, even a minor one. Suspension work, new tires, or significant changes in how you load your vehicle can also shift the beam slightly. If you notice oncoming drivers flashing their lights at you, that is a sign your headlights may be too high.
Can I adjust my headlights if my car is parked on a slight slope?
No. Even a small slope will throw off the vertical aim. Park on a level surface — a flat driveway or parking lot — before you adjust. If your driveway slopes, use a parking lot or ask a neighbor if you can use theirs.
What if one headlight is much brighter than the other?
That is usually a bulb issue, not an aim issue. A dimmer bulb or a bulb nearing the end of its life will appear lower or weaker even if both lights are aimed correctly. Replace the bulb first, then check the aim. If both bulbs are new and one light is still dimmer, the reflector inside that housing may be damaged.
Do I need to adjust my headlights after replacing a bulb?
Not usually. Replacing a bulb does not change the aim of the light. However, if the old bulb was burned out or very dim, you may notice for the first time that the aim is off. Check the aim after installing a new bulb to see if adjustment is needed.
Will adjusting my headlights myself pass a vehicle inspection?
Yes, if you do it correctly. Inspection stations use the same principle — aiming the beam at a specific height on a wall — that you use at home. If your adjustment matches that standard, your car will pass. If you are unsure, many inspection stations will check your aim before the formal test and tell you if adjustment is needed.