Suppose your maintenance calories are 2000cal/day and you want to loose 1 kg weight in 10 days, to loose 1 kg you need to create total deficit of 7700cal in 10 days... 1d calories=2000 10d cal = 2000×10 =20,000 To loose 1kg in 10d, => 20,000-7,700=12,300 => 12,300/10= 1230 cal per day You'll loose 1kg in 10 day with sedentary life style , you can loose more with exercise etc etc HOPE it helps.