02 — EARTH CURVATURE CALCULATOR

What lies beyond the horizon?

Calculate how much of a distant object is hidden by the curvature of the Earth.

01

Inputs

02

Results

Part of the target remains visible.

Horizon distance4.99km
Hidden height42.709m
Visible height57.291m
Curvature drop61.45m
Model

Spherical Earth with a 6,371 km radius. Refraction is approximated using an effective Earth radius.

Calculation logic adapted and extended from earthcalc by Andy Cook (MIT License). License notice ↗

GUIDE

Earth Curvature Calculator

See how Earth curvature, observer height and atmospheric refraction affect the visibility of distant objects.

How to use this tool

Enter eye height, distance and target height. Select refraction if needed and read horizon distance, curvature drop, visible and hidden height.

Frequently asked questions

Is this tool free?

Yes. You can use it free of charge and without registration in your browser.

Are my inputs stored?

The calculation runs in your browser. Inputs are not permanently stored for the tool to work.

Does it work on mobile devices?

Yes. The interface is optimized for phones, tablets and desktop computers.