How many calories do i need to shed in order to lose 1 kg?

i know that energy cannot be converted into m but is there any way of finding out how many calories do i need to shed in order to lose 1 kg? because i need to lose 6 kgs in 2 weeks.if any1 knows any quick methods then pl let me know. i really wud like to know how many calories makes 1 kg.thanks!