Understanding the Moore/Marsden Calculation in California Divorce Cases

A Moore/Marsden calculation is one of the more complicated formulas in California Family Law. This calculation is used when, at the time of divorce, there was a separate property home, but community property funds were used to pay down the mortgage or make other improvements on the home. The law provides that under these facts, the community estate “acquires a pro tanto interest” in the other party’s separate property “’[w]hen community property is used to reduce the principal balance of a mortgage ‘” on the property.

But there is still confusion regarding how this formula works. In the Case of Marriage of Freeman (2025) 2025 DJDAR 2978, the California Court of Appeal tried to make all of this easier to understand.  The pro tanto percentage, once calculated, is multiplied by the total value of the property to determine the dollar value of the community’s interest. “We publish this case, “ the Freeman justices wrote, “to clarify that the community’s pro tanto percentage interest is calculated as of the time of the parties’ separation, while the value of the property is generally determined as near as practical to the time of trial.”

In the Freeman case, a number of experts testified as to the value of the property at issue, Micheltorena. The trial judge found that there was a 60.2 percent community interest in the Micheltorena property based on the amount of principal paid and improvements made during the parties’ relationship. The justices held the community’s interest in the home stopped accruing after separation. But again, the home’s valuation itself, is to be determined as close as practical as the trial date. This is based on Family Code section 2552, which states in relevant part, “the court shall value the assets and liabilities as near as practicable to the time of trial.  (Itatlics in original.)

This 3-0 decision, by the Court of Appeal out of Riverside County, represents an affirmation of the trial court. The Freeman case is now binding precedent on all California trial courts.