Horizzn, assuming earth is a sphere with a radius of 6371 kilometers we can use the Pythagorean Theorem and accurately calculate the distance to the horizon and how much a distant object is obscured by the horizon.

Calculating the Earth curvature with Horizzn Calculator is a simple two-step process. We recommend you use Horizzn out in the open with a clear sight to the horizon so you can try and match your calculations with real-life observations.