A great resource to help calculate your laps, work out approximate times, and any elevation gain on the descent is The Everesting Calculator.
Take caution when calculating your reps/laps based on Strava segments, as these only show ‘elevation difference’ and not ‘elevation gain’ (i.e. if your climb has a few descents you want to ensure you are calculating laps based on the total elevation gain, and not simply the difference between the base and summit). It is strongly suggested that you check the listed elevation gain against your own recording.
It is our strong recommendation that on the day you ride to a pre-determined amount of reps/laps, as opposed to the figure on your bike computer, particularly on a day of weather changes.
The purest and most accurate method of climbing 8,848m will always be to divide 8,848m by the amount of elevation on your carefully selected segment to give you the laps required.
(e.g. a segment of 100m gain: 8,848 ÷ 100m = 88.48 reps required)