The calories burned will depend on your weight and the speed of jump. According to the article below, if you're 160 lbs and jump at 125 beats per minute, then you'd burn about 100 calories per 1000 skips as it'll take about 8 minutes. If you weight 200 lbs, a rough guess would be 125 calories per 1000 skips at 125 skips per minute. Or if you're 120 lbs, then you'd burn about 75 calories. If you jump slower than that, then you'd burn less, but not a whole lot less. I don't think it's more than 10% variant. Just a guess. A good ballpark figure is 10 skips for 1 calorie. Hope this helps.
According to the Mayo Clinic, jumping rope is among the most effective exercises for burning calories. A 160-pound person burns about 730 calories in 60 minutes of jumping rope. A 200-pound person burns about 910 calories and a 240-pound person burns approximately 1,090 calories. Jumping 600 times will not take 60 minutes. According to What's Cooking America, if you jump at a rate of 70 times per minute, you can estimate the number of calories you burn per minute by multiplying your body weight by .074. If you do 125 jumps per minute, multiply your body weight by .080 to estimate the calories you burn in a minute. If you are faster on your feet and do 145 jumps per minute, estimate the number of calories you burn per minute by multiplying your weight by .089. You can then multiply that value by the number of minutes it takes you to complete 600 jumps www.livestrong.com/article/446726-how-many