About the Horizon Distance Calculator
How far you can see to the horizon from any height, with and without atmospheric refraction.
Also known as: how far is the horizon, line of sight distance, visible horizon, distance to horizon.
How to use this calculator
- Enter eye height above sea level, height of the object you are looking at.
- The result updates instantly as you type — press Calculate (or Enter) at any time.
- Review the breakdown shown under the main result.
- Use Copy result or Share to save the answer or send a link with your inputs.
Formula
d ≈ 3.86 × √h (km, h in metres, with refraction)
Worked example
Using the values pre-filled in the calculator above:
- Eye height above sea level = 1.7 m
- Height of the object you are looking at = 0 m
the calculator returns:
- Horizon distance: 5.033 km
- Geometric (no refraction): 4.654 km
- In miles: 3.127
- In nautical miles: 2.718