这里写长篇论文不挣钱，我只是粗略地给楼主一个概念。

离婚案件各不相同，无法像你所说1000/2=500.  

http://www.divorcenet.com/resources/divorce-judge/how-judge-decides-alimony-amount.htm

Basically, in setting the amount of alimony to be paid, courts look at:

• how much money each person could reasonably earn every month
• what the reasonable expenses are going to be for each of them, and
• whether an alimony award from one to the other would make it possible for each to go forward with a lifestyle somewhat close to what the couple had before they split—known in divorce law as “the standard of living established during the marriage.”

十六年婚姻感情这个东西，无法完全靠算术啊。