Net family property (NFP) is how much money a married partner is worth at the end of the relationship after taking into account what they brought into the marriage.
To calculate a married partner's NFP, usually you add together all assets minus all debts that they had on the day they separated from their partner. Then you also subtract all assets minus all debts they had on the date of marriage. Some assets or debts are treated differently in this calculation. For example, some gifts and inheritances are not included.