How to Align Your Car's Headlights in 20 Minutes

Why Headlight Alignment Matters

Over time, bumpy roads, potholes, and minor fender benders can cause your car's headlights to shift out of alignment. When headlights point too high, they blind oncoming drivers; when they point too low or to the side, your nighttime visibility is drastically reduced. Fortunately, you don't need an expensive trip to the mechanic to fix this. With a tape measure, some painter's tape, and a screwdriver, you can perfectly align your headlights in about 20 minutes.

Tools and Materials Needed

• A flat wall or garage door with at least 30 feet of flat ground in front of it.
• Painter's tape or masking tape.
• A tape measure.
• A screwdriver (usually Phillips, or a socket wrench depending on your vehicle model).
• A dark towel or piece of cardboard to block one headlight at a time.

Step 1: Prepare Your Vehicle

Before making any adjustments, you must ensure your car is sitting at its normal riding height. Park on completely level ground. Check that your tire pressure is correct across all four tires. Ensure your gas tank is at least half full, and make sure there is no heavy cargo in the trunk. These variables can alter the angle of your vehicle and throw off your measurements.

Step 2: Mark the Headlight Centerlines

Pull your car up as close as possible to the flat wall or garage door. Using your painter's tape, mark a precise vertical line directly in front of the center of each headlight lens. Then, run a single horizontal line of tape across the wall that connects both vertical marks, aligning directly with the center height of your headlights. This creates a clear crosshair for each headlight on the wall.

Step 3: Back Up Exactly 25 Feet

Using your tape measure, measure exactly 25 feet straight back from the wall. Keep your steering wheel completely straight as you back up. Turn on your low-beam headlights.

Step 4: Locate the Adjustment Screws

Pop your hood and locate the headlight adjustment screws. They are usually located on the top or back of the headlight housing assembly. Many cars have two screws per headlight: one for vertical adjustment (up/down) and one for horizontal adjustment (left/right). They may be recessed, so you might need a flashlight to spot them. If you cannot find them, consult your vehicle's owner manual.

Step 5: Adjust the Vertical and Horizontal Aim

To adjust accurately, cover one headlight with a dark towel or cardboard so you can focus on one beam at a time. Look at the light pattern on the wall. The brightest part of the beam (the "hotspot") should be adjusted using your screwdriver:

• Vertical Adjustment: Turn the vertical screw until the top edge of the brightest part of the beam sits exactly 2 inches below the horizontal tape line. This prevents your lights from blinding oncoming drivers.
• Horizontal Adjustment: Turn the horizontal screw until the brightest part of the beam is centered slightly to the right of your vertical tape mark. This keeps the light focused on your lane and the shoulder of the road, rather than shining directly into oncoming traffic.

Once the first headlight is set, swap the cover to the other headlight and repeat the exact same adjustment process.

Step 6: Test Your Work

Remove the cover from both headlights and inspect the pattern on the wall. The two beams should be completely level with each other and slightly lower than your original horizontal tape line. Take your car for a short test drive on a dark road to ensure your path is brightly lit without throwing light high into the trees or oncoming windshields.