The City of San José processes requests for payoff demands of existing homebuyer and home repair loans, and affordability restrictions (i.e. Depending on your lender, you may have to sign in to an online account, call a helpline, or send a formal letter to start the request process.The mortgage payoff calculator helps you find out. If you look carefully at the closing settlement statement, you will find the mortgage balance plus 27 days of interest have been paid to the lender. They'll figure out the amount at closing and you'll get the right amount. 1) Call the mortgage department and request an official principal payoff letter. Subtract your down payment from the purchase price of the house. Add to this any closing costs you plan to finance (or roll into the mortgage). Use SmartAsset's free California mortgage loan calculator to determine your monthly payments, including PMI, homeowners insurance, taxes, interest and more. NerdWallet's early mortgage payoff calculator figures out how much more to pay.