Adjust headlights by turning the adjustment screws behind or below each headlight unit

Most headlights can be aimed higher or lower using two screws located on the back or underside of the headlight housing. One screw controls vertical aim (up and down), and the other controls horizontal aim (left and right). You can reach these screws by opening your hood and locating the adjustment mechanism on the rear of the headlight assembly — no special tools are required beyond a Phillips or flathead screwdriver, depending on your vehicle's design.

Before you adjust, park on level ground facing a wall or garage door about 25 feet away in a dark space. Turn on your low-beam headlights and mark the center of each beam on the wall with tape. The beam should hit slightly below the horizontal line at eye level and point straight ahead, not upward. If your beams are too high, too low, or angled wrong, you can correct them by turning the adjustment screws a quarter-turn at a time and checking the result.

Key Takeaways

  • Headlight adjustment screws are located on the back or underside of the headlight housing and require only a screwdriver to turn.
  • One screw adjusts vertical aim and one adjusts horizontal aim; turn them slowly in quarter-turn increments to avoid over-correcting.
  • Test your adjustment by parking 25 feet from a wall in darkness and checking that both beams point straight ahead and slightly downward.
  • If you cannot locate the adjustment screws or your headlights are sealed units, your vehicle may require a mechanic or dealership service.

Where to find the adjustment screws on your headlight

Open your hood and look directly behind the headlight unit you want to adjust. Most vehicles have two screws visible on the back of the housing. On some cars, especially newer models, the screws may be on the underside of the headlight assembly, requiring you to reach up from below or remove the wheel well liner to access them. Check your owner's manual for the exact location — it will show a diagram of your specific headlight assembly.

If you see only one screw, it may control both vertical and horizontal aim through a single mechanism, or the second screw may be hidden behind a plastic cover. Gently pry off any covers with a flathead screwdriver. If the headlight is a sealed unit with no visible screws, your vehicle uses a different adjustment system — some newer cars have motorized adjusters controlled from inside the cabin, or the headlight may need to be removed and adjusted by a technician.

Vertical adjustment: aiming headlights up or down

The vertical adjustment screw typically sits on top of or below the headlight housing. Turning this screw clockwise usually raises the beam, and turning it counterclockwise lowers it. Make one quarter-turn, walk back to your test wall, and observe where the beam moved. If it went the wrong direction, turn the screw the opposite way. Continue adjusting in small increments until the beam center sits just below eye level on the wall.

Proper vertical aim prevents blinding oncoming drivers while keeping the road ahead well-lit. If your headlights point too high, you create glare that makes it harder for other drivers to see. If they point too low, you lose visibility on the road. The goal is a beam that illuminates the pavement 10 to 15 feet ahead of your car without climbing toward the sky.

Horizontal adjustment: aiming headlights left or right

The horizontal adjustment screw is usually positioned to the side of the headlight housing. Turning this screw adjusts whether the beam points slightly inward (toward the center of the car) or outward. Most vehicles aim the low beam slightly inward so both beams converge slightly ahead of the car, improving visibility without creating a gap in the middle of the road.

To check horizontal aim, stand to the side and observe whether both beams point straight ahead or if one angles outward. If one beam points too far to the side, turn its horizontal screw to bring it back in line with the other. Make quarter-turn adjustments and recheck from your test position. Proper horizontal aim ensures even illumination across the road and prevents one side from being darker than the other.

Testing your adjustment before driving

After adjusting both screws, turn off your headlights and move your car back to the 25-foot mark. Turn the lights on again and check the beam pattern on the wall. Both beams should be at the same height, point straight ahead, and sit just below eye level. If one beam is higher or lower than the other, or if they point in different directions, make additional quarter-turn adjustments to the offending headlight.

Once both beams look correct on the wall, drive to a dark road with no oncoming traffic and verify that the adjustment feels right while driving. You should see the road clearly ahead without excessive glare bouncing back at you. If oncoming drivers flash their lights at you, your headlights are still too high — lower them further and retest.

When to have a professional adjust your headlights

If your headlight housing has no visible adjustment screws, or if the screws do not move when you turn them, the adjustment mechanism may be broken or the headlight may be a sealed unit. Some vehicles use motorized headlight leveling systems that adjust automatically based on how heavily loaded your car is. In these cases, a mechanic or dealership can diagnose the problem and repair or replace the headlight assembly if needed.

You should also seek professional help if your headlights are misaligned due to a collision or accident. Impact damage can bend the headlight housing or the mounting bracket, making manual adjustment impossible. A technician can measure the alignment with specialized equipment and either adjust the mounting bracket or replace the headlight entirely.

Frequently Asked Questions

Do I need special tools to adjust my headlights?

No. A Phillips or flathead screwdriver is usually all you need. Some vehicles may require a socket wrench if the adjustment screws are recessed, but most cars use screws you can turn by hand with a basic screwdriver. Check your owner's manual to confirm what tools fit your specific model.

How often should I adjust my headlights?

Headlights rarely drift out of aim on their own unless your car is in an accident or you hit a large pothole. If you notice your headlights pointing the wrong direction, adjust them when ready. Some people check alignment once a year as part of routine maintenance, but it is not necessary unless something feels off.

Can I adjust my headlights while the engine is running?

Yes, but it is safer to turn off the engine first. You will be reaching behind the headlight housing, and having the engine off eliminates the risk of moving parts or heat from the engine. Turn on the headlights before you start adjusting so you can see the beam on your test wall, then turn the engine off while you work.

What if one headlight is much brighter than the other?

Brightness difference usually means one headlight bulb is older or failing, not an aim problem. If both bulbs are the same age and one still looks dimmer, replace that bulb. If the brightness is equal but the beams point in different directions, adjust the horizontal or vertical screws as described above.

Will adjusting my headlights affect my high beams?

Usually not. Low beams and high beams are separate filaments inside the same bulb, and they share the same housing. Adjusting the housing aim affects both beams equally. However, if your high beams seem misaligned after adjusting low beams, check that you adjusted the correct headlight and that both screws are tight.