Visibility Distance Calculator
Distance to Horizon
Calculate how far you can see from a given height
Line of Sight (Two Heights)
Can two elevated points see each other?
Common Viewpoints
Horizon distance from common elevations
Formula
d (miles) = √(2Rh) × 1.08 refraction correction | R = 3,959 miles (Earth radius) | h in miles = feet / 5,280
Frequently Asked Questions
How far can you see from sea level?
Standing at the beach with your eyes about 6 feet above sea level, the geometric horizon is about 3 miles away. With atmospheric refraction, it extends to about 3.2 miles. From a ship's bridge at 50 feet, you can see about 8.6 miles.
How far can you see from a mountain?
From a 5,000-foot summit, you can see about 86 miles to the horizon. From a 14,000-foot peak (like Colorado 14ers), the horizon is about 145 miles. From Mt. Everest (29,032 ft), the theoretical horizon is about 210 miles.
What affects actual visibility?
Besides Earth's curvature, visibility is limited by: atmospheric haze and humidity (typical clear day visibility is 20-40 miles), air pollution, rain/fog, dust, and the contrast/size of the target. Mountain peaks can sometimes be spotted beyond 200 miles in exceptionally clear conditions.
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