What is the distance beween...?

Question

What is the distance in miles between Sea level and outer space?

Answer 1

There is no definite boundary between Earth and Space.  The Earth's atmosphere gradually gets thinner and thinner.  A good estimate would be about 100 km (62 miles) above the Earth's surface.

Answer 2

The upper limit of the atmosphere is usually given as 120 miles; no definitive figure is possible, since there is no boundary line between the incredibly attenuated gases 120 miles up in space.