Headlight Aim Height Calculator
Calculate the correct headlight aim height for any vehicle and distance.
Properly aimed headlights improve safety and avoid blinding other drivers.
Properly aimed headlights are critical for nighttime driving safety. Headlights aimed too high blind oncoming drivers and cause dangerous glare. Too low and they illuminate only the road directly in front of you, reducing your warning time for hazards ahead.
How Headlight Aiming Works
The standard method for checking and adjusting headlights requires a flat surface, a wall (or garage door), and a tape measure. The principle is simple: project the headlight beam onto a wall at a known distance, and measure where the center of the beam hits.
The beam center should be slightly BELOW the height of the headlight center on the car. This slight downward angle is intentional — it illuminates the road ahead while preventing glare for oncoming drivers.
The Standard Formula
For every 25 feet (7.6 m) of distance from the wall, the beam should drop approximately 2 inches (5 cm) below the headlight center height.
Drop per foot = (2 inches ÷ 25 feet) = 0.08 inches per foot of distance Drop per meter = (5 cm ÷ 7.6 m) = 0.66 cm per meter of distance
Target Aim Height at Wall
Wall aim height = Headlight center height − (Distance to wall × drop rate)
Standard Testing Distances
| Distance to Wall | Expected Drop |
|---|---|
| 25 ft (7.6 m) | 2 in (5 cm) |
| 10 ft (3 m) | 0.8 in (2 cm) |
| 15 ft (4.6 m) | 1.2 in (3 cm) |
| 7.5 ft (2.3 m) | 0.6 in (1.5 cm) |
What “On Center” Means
Most headlights have a small aiming indicator or bubble level visible through the lens or in the access hole. When using a wall, look for the “hot spot” — the brightest part of the beam — not the outer edge.
After Adjustment
Always verify both headlights separately. With a passenger or heavy load in the rear, headlights aim higher — check alignment under loaded conditions if you frequently carry cargo.
Regulations
Most countries regulate headlight aim. In the United States, FMVSS 108 governs headlamp output and aim. In Europe, ECE Regulation 48 applies. Improperly aimed lights can result in a failed vehicle inspection.