The basic steps to aim your headlights correctly

Most headlights can be adjusted by turning a screw or bolt located on the back or side of the headlight housing, either by hand or with a screwdriver. On many cars, there are two adjustment screws per headlight — one controls the up-and-down angle, and the other controls left-and-right aim. Before you adjust, park on level ground about 25 feet from a wall or garage door in a dark space, turn on your low-beam headlights, and mark the center of each beam on the wall with tape.

The goal is to aim each beam so the brightest spot sits slightly below and to the right of the center mark (in countries that drive on the right side of the road). This prevents blinding oncoming drivers while still lighting the road ahead. If your car has automatic headlight leveling, you may need to reset it before adjusting, or the system will fight your manual changes.

Key Takeaways

  • Adjustment screws are usually found on the back or inner side of the headlight housing and turn with a screwdriver or by hand.
  • Park 25 feet from a wall in darkness, mark the beam centers with tape, and aim so the brightest spot is slightly below and to the right of center.
  • One screw controls vertical aim and one controls horizontal aim, though some headlights have only one adjustment point.
  • If your headlights are severely misaligned or the adjustment screws are stuck or missing, a mechanic or dealership can realign them with specialized equipment.

Locating the adjustment screws on your headlight

Open your hood and look at the back of the headlight housing. Most cars have two small screws or bolts visible there — one positioned toward the top or bottom (vertical adjustment) and one positioned toward the inner or outer edge (horizontal adjustment). Some vehicles mount the screws on the side of the housing instead of the back. Consult your owner's manual if you cannot find them, as the location varies by make and model.

Before turning anything, check whether the screws move freely. If a screw is stuck or corroded, forcing it can strip the threads or break the housing. A light spray of penetrating oil left for a few minutes can help loosen a stuck screw. If the screw still will not budge, stop and take the car to a mechanic rather than risk damage.

Setting up your wall test and marking the beam

Find a level, dark space — a garage, driveway, or empty parking lot works well. Park your car perpendicular to a flat wall or garage door, exactly 25 feet away. Measure this distance; it matters because the beam pattern changes with distance. Turn on your low-beam headlights (not high beam) and close the hood.

Use masking tape to mark the center of each headlight beam on the wall. Mark the highest point of the bright spot and the center left-to-right. Step back and look at the overall pattern. The beam should form a clear, defined shape — if it is scattered or dim, the headlight lens may be cloudy or the bulb may be failing, which adjustment cannot fix.

Adjusting the vertical and horizontal aim

Start with the vertical adjustment (up-and-down). Turn the vertical screw slowly — usually clockwise raises the beam and counterclockwise lowers it, though this varies by car. Turn a quarter turn, step back, and look at where the beam hits the wall. Adjust until the brightest spot sits about 2 inches below the center mark you made. This prevents the beam from climbing into oncoming drivers' eyes on the road.

Next, adjust the horizontal screw (left-and-right aim). The goal is to center the beam left-to-right, with a slight bias toward the right side of the road (in right-hand-drive countries). Turn the screw in small increments and check your progress on the wall after each adjustment. Once both beams are aimed, turn off the headlights, close the hood, and test them on the road at night to confirm they feel right.

What to do if the screws are stuck or missing

Corroded or stuck adjustment screws are common on older cars or cars in wet climates. If a screw will not turn after a light process of penetrating oil, do not force it — you risk stripping the threads or cracking the plastic housing. A dealership or independent mechanic can remove and replace the screw, or realign the headlight using a headlight aiming machine, which is a specialized tool that reads the beam angle electronically.

If a screw is missing entirely, the headlight will drift out of aim over time. A replacement screw costs a few dollars, but you need the correct part number for your car. Your dealership parts department or an independent shop can order it and install it, then aim the headlight properly.

When automatic headlight leveling affects your adjustment

Many newer cars have automatic headlight leveling systems that adjust the beam angle based on how much weight is in the car (passengers, cargo) and the car's suspension height. If your car has this system, it may override manual adjustments or make them harder to see. Check your owner's manual to see whether you need to disable or reset the system before adjusting.

Some systems have a manual dial on the dashboard or a setting in the infotainment menu that lets you choose a fixed level for testing. Set it to the middle position or the position labeled for normal driving, then make your wall test. After you finish adjusting, return the system to automatic mode if that is how it normally operates.

Frequently Asked Questions

How often should I check my headlight aim?

Check your headlight aim once a year or after any collision, pothole impact, or suspension work. Normal driving does not usually knock headlights out of aim, but rough roads and accidents do. If you notice your headlights seem dimmer or the beam pattern looks odd, aim may have shifted.

Can I adjust my headlights during the day?

You can locate and turn the screws during the day, but you cannot see the beam pattern on the wall. Always do the actual aiming test at night or in a dark space so you can see where the light actually lands. Daytime adjustments are guesswork.

What if one headlight is much brighter than the other?

Uneven brightness usually means one bulb is older or failing, not an aiming problem. Both bulbs should be the same age and type. If replacing the bulb does not fix it, the lens on the dimmer side may be cloudy or the reflector inside may be damaged, which aiming cannot repair.

Do I need special tools to adjust headlights?

Most headlights use Phillips or flathead screws that turn with a standard screwdriver. Some use bolts that need a wrench or socket. Check your owner's manual to see what size tool fits your car. You do not need a headlight aiming machine for basic adjustment — the wall test works fine.

Should I adjust my high beams too?

Yes, high beams should also be aimed, though they are usually adjusted separately from low beams. The same wall test and screw locations explore. High beams should point higher and farther down the road than low beams, so aim them accordingly and check your owner's manual for the recommended beam height.