There is no simple formula to spousal support. Whereas child support is an algebraic formula provide by CA Family Code 4055, spousal support is not exactly determined via formula.
In Los Angeles, the courts may use Dissomaster (child support program) to calculate temporary spousal support, but this is not for sure, and permanent support is not dependent on Dissomaster. The Los Angeles County Department of Child Support Services also provides a free child support calculator located here. For more information, please ask your lawyer.