Sorry for the long post but it is the Engineer in me.
The problem is not distance but time dependant and is completely dependant on individual’s fitness, height (length of stride), and percent grade being taken, but here goes a typical example for me to illustrate the point.
On an ascent of a grade of about 20% with a fully loaded pack I typically pull about 0.5 miles per hour with a stride of about 18”. So in a 1 hour’s time I would travel a horizontal distance 2640 ft and a vertical distance of 528 ft. So to get the equivalent of 1000 ft vertical on a 20% slope = (2640*1000)/528 = 5000 ft horizontal or 0.94 miles, which takes 1.88 hours to cover.
Descending I can cover around 2 miles per hour with a stride of a little over 3 feet. For the same grade as outlined above and same duration of 1 hour. I would travel a horizontal distance of 10,560 ft and a vertical distance of 2112 ft. So to get the equivalent of 1000 ft vertical on a 20% slope = (10560*1000)/2112 = 5000 ft horizontal or 0.94 miles but takes 0.47 hours to cover.
So as the example shows the vertical and horizontal relationships are the same but it is the time it takes to cover what is different, of course this assumes the same conditions for ascending and descending. So for me it is add 1.88 hours for a gain and 0.47 hours for a loss in elevation.
