Legal Question in Family Law in California

There is no absolute rule, but the baseline the courts start from is 1/2 the lengtht of the marriage. The 10 year rule you may have heard of affects jurisdiction over future support and changes to support, not the lenght of support ordered.

Many factors influence post judgment spousal support. Length of the marriage is one of them. The court also considers the age of the parties, earning capacity, health and standard of living during the course of the marriage. All these factors influence duration and amount of spousal support.