8" per mile squared

That's just an approximation that is practical only for short distances (say, up to 1000 miles). None of the curvature calculators use it, AFAIK. Here's a list of some of them:

• walter.bislins.ch
• earthcurvature.com
• dizzib.github.io

And here's a graphic that shows how the curvature is calculated.

8" per mile squared

That's just an approximation that is practical only for short distances (say, up to 1000 miles). None of the curvature calculators use it, AFAIK. Here's a list of some of them:

• walter.bislins.ch
• earthcurvature.com
• dizzib.github.io

And here's a graphic that shows how it's calculated.

8" per mile squared

That's just an approximation that is practical only for short distances (say, up to 1000 miles). None of the curvature calculators use it, AFAIK. Here's a list of them:

• walter.bislins.ch
• earthcurvature.com
• dizzib.github.io

And here's a graphic that shows how it's calculated.