What your home is worth depends on why you ask the question. It could be one value based on a purchase or sale and an entirely different value for insurance purposes.
Fair market value is the price a buyer and seller can agree upon assuming both are knowledgeable, willing and unpressured by extraordinary events. This value is generally indicated by the Comparable Market Analysis (or CMA for short) done by real estate professionals.
Insured value is determined for the proper insurance coverage. Replacement cost could actually exceed the cost of new construction when additional expenses are incurred for demolition and the added complexities of matching existing construction.
Homeowners are generally more familiar with their home's market value. Since it can be lower than the replacement cost, owners should review the insured value with their property insurance agents periodically. Under-insuring could invoke a co-insurance clause that may limit the settlement and increase your out of pocket expenses.