那要看你用的卡是卡路里还是大卡了,一卡路里大约等于4.2焦耳,一千卡就是4200焦,即4.2千焦,0.0042兆焦,0.0000042吉焦；如果是大卡,一大卡等于1000卡路里,因此为4200千焦,4.2兆焦,0.0042吉焦.