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Earth Curvature Calculator

How much the Earth curves away over a distance, and how much of a distant object is hidden.

Enter values

Results update as you type.

Result

Curvature drop

7.848 m

Horizon distance from your eye height
4.654 km
Hidden height of a distant object
2.243 m
Drop in feet
25.75
Beyond the horizon by
5.346 km

About the Earth Curvature Calculator

How much the Earth curves away over a distance, and how much of a distant object is hidden.

Also known as: curvature drop, how much does earth curve, earth curve per mile, hidden height.

How to use this calculator

  1. Enter distance, units, observer height.
  2. The result updates instantly as you type — press Calculate (or Enter) at any time.
  3. Review the breakdown shown under the main result.
  4. Use Copy result or Share to save the answer or send a link with your inputs.

Formula

drop ≈ d² / 2R · horizon = √(2Rh)

Worked example

Using the values pre-filled in the calculator above:

  • Distance = 10
  • Units: Kilometres
  • Observer height = 1.7 m

the calculator returns:

  • Curvature drop: 7.848 m
  • Horizon distance from your eye height: 4.654 km
  • Hidden height of a distant object: 2.243 m
  • Drop in feet: 25.75