How to adjust your headlights yourself

Most headlights can be adjusted by turning screws or bolts located on the back or side of the headlight housing inside the engine bay. You'll typically find two adjustment screws per headlight — one controls vertical aim (up and down) and one controls horizontal aim (left and right). The exact location and type of fastener varies by vehicle make and model, so check your owner's manual first to find where yours are located and whether they use Phillips head screws, hex bolts, or another type.

The adjustment process itself takes 15 to 30 minutes and requires only a screwdriver or wrench that fits your vehicle's fasteners. You'll need a flat, level surface like a driveway or parking lot, and ideally a wall or garage door to aim at. Some vehicles have adjustment knobs inside the cabin near the headlight switch instead of screws in the engine bay — if that's your car, the manual will show you exactly where they are and which direction to turn them.

If you're uncomfortable working in the engine bay or can't locate the adjustment screws, a mechanic or tire shop can do this in under an hour, usually for $20 to $50 per vehicle. Many shops include this as part of a headlight replacement or during routine maintenance.

Key Takeaways

  • Headlight adjustment screws are located on the back or side of the headlight housing in your engine bay, with one screw controlling vertical aim and one controlling horizontal aim.
  • You can adjust them yourself with a screwdriver or wrench, a level surface, and a wall to aim at — the process takes 15 to 30 minutes.
  • Your owner's manual shows the exact location of adjustment screws and which direction to turn them for your specific vehicle.
  • A mechanic or tire shop can adjust your headlights for $20 to $50 if you prefer not to do it yourself.
  • Misaligned headlights reduce your visibility at night and can blind oncoming drivers, so adjustment is worth doing if your lights are aiming too high or too low.

Finding the adjustment screws on your vehicle

Open your hood and look directly behind each headlight. Most vehicles have the adjustment screws mounted on the back of the headlight assembly itself. On some cars, especially older models, the screws are on the side of the housing. You may need to remove a rubber cover or plastic trim piece to access them — these typically pull or unclip without tools.

If you can't spot them in the engine bay, check your owner's manual for a diagram showing their location. Some vehicles hide the screws behind the bumper or require partial removal of the headlight assembly. A few newer cars use motorized adjusters controlled by knobs or buttons inside the cabin near the headlight switch — if that's the case, your manual will explain how to use them.

Once you've located the screws, note which one is which. The screw that moves the light up and down is usually positioned vertically or at an angle, while the screw that moves it left and right is usually positioned horizontally. Turning them clockwise or counterclockwise will move the beam in different directions — your manual will specify which way to turn for which direction.

How to aim your headlights correctly

Park your vehicle on a level surface about 25 feet away from a wall or garage door. Turn on your low-beam headlights and observe where the beam hits the wall. The beam should be aimed so that the brightest part of the light hits slightly below the horizontal center of the wall, and the light should be centered left-to-right on your side of the vehicle.

If the light is too high, turn the vertical adjustment screw to lower it. If it's too low, turn it to raise it. Make small adjustments — a quarter turn at a time — and step back to check the beam after each adjustment. Once the vertical aim looks correct, adjust the horizontal screw if the beam is tilted too far left or right.

The goal is to have both headlights aiming at the same spot on the wall so they're parallel to each other. Uneven headlights will cause one side of the road to be brighter than the other, reducing your visibility and potentially blinding oncoming drivers in the other lane.

When to adjust your headlights

Adjust your headlights if you notice they're aiming too high (blinding oncoming drivers), too low (reducing your visibility), or off to one side. This often happens after a collision, even a minor one, because the impact can shift the headlight housing slightly. It can also happen gradually if your vehicle's suspension settles or if you've added weight to the back of your car.

If you've recently replaced a headlight bulb or assembly, check the aim afterward — new parts may not be positioned exactly the same as the old ones. Similarly, if you've had suspension work done or added a roof rack or cargo carrier, the vehicle's ride height may have changed enough to throw off the headlight aim.

Some states include headlight aim as part of vehicle inspection requirements, so if your inspection failed for this reason, adjustment is necessary before you can pass. Check your state's inspection requirements to see if headlight aim is tested in your area.

Differences between low-beam and high-beam adjustment

Most vehicles only have adjustment screws for the low-beam headlights. High beams are typically fixed in position and cannot be adjusted. If your high beams are aiming incorrectly, the problem is usually a bent headlight housing or a misaligned bulb inside the housing, which requires replacement rather than adjustment.

When you adjust the low beams, make sure your headlight switch is set to low beam, not high beam or parking lights. The aim of the low beam is what matters for safe visibility and for passing inspection, since high beams are only used occasionally and are expected to be brighter and higher than low beams.

What to do if you can't adjust them yourself

If the adjustment screws are stuck, stripped, or impossible to reach without removing other parts, a mechanic can handle it. Shops with headlight aiming equipment can also do a more precise job than aiming by eye at a wall — they use a device called a headlight aimer that measures the exact angle of the beam and ensures both lights are perfectly aligned.

Expect to pay $20 to $50 for this service at most independent shops or tire stores. Dealerships may charge more. If you're having other work done on your vehicle, ask if they can check and adjust your headlights at the same time — many shops will do a quick visual check for free as part of routine maintenance.

If the headlight housing itself is cracked, cloudy, or damaged, adjustment won't solve the problem — the housing will need to be replaced. A mechanic can tell you whether adjustment alone will fix your visibility issue or whether replacement is necessary.

Frequently Asked Questions

Can I adjust my headlights if I have HID or LED headlights?

Yes, HID and LED headlights use the same adjustment screws as standard halogen bulbs. The adjustment process is identical — only the type of bulb inside the housing is different. If you've recently upgraded to HID or LED bulbs, check the aim afterward because the new bulbs may produce a slightly different beam pattern than the old ones.

What if one headlight is brighter than the other after I adjust them?

Brightness difference usually means one bulb is older or failing, not an aim problem. Both headlights should be aimed at the same spot on the wall. If they are and one still looks dimmer, replace the dimmer bulb. If the beams are aimed at different spots, continue adjusting until they match.

Do I need to adjust my headlights after replacing a bulb?

Not usually, unless the bulb was installed incorrectly or the housing was disturbed during replacement. If you only changed the bulb and didn't touch the housing, the aim should remain the same. If the aim looks off after a bulb replacement, check that the new bulb is seated fully in the socket and that the housing wasn't bumped during the work.

Will adjusting my headlights affect my vehicle inspection?

Proper headlight aim is required to pass inspection in most states. If your inspection failed for headlight aim, adjustment will fix the problem. After you adjust them, you can return for re-inspection — the fee for re-inspection varies by state and testing facility.

What if my headlights have no visible adjustment screws?

Some vehicles have adjustment controls inside the cabin instead of in the engine bay. Check your owner's manual for the location of headlight aim controls — they may be knobs or buttons near the headlight switch. If your manual shows no adjustment option, the headlights may be fixed and non-adjustable, which is common on some newer vehicles with sealed beam units.