Build your estimate
Every assumption is editable. Watchdog does not insert a current mortgage rate, a universal closing-cost percentage, or an estimated property tax bill behind the scenes.
What this calculator includes
The monthly estimate combines mortgage principal and interest with property tax, homeowners insurance, HOA dues, mortgage insurance and a user-controlled maintenance reserve. The upfront estimate combines the down payment with a user-entered buyer closing-cost assumption, then subtracts any credits or assistance you enter.
For a property-specific tax input, use the NJ Property Tax Estimator or start with a Watchdog property lookup. For definitions and New Jersey property-tax context, use the Watchdog glossary and town and county reports.
Why the closing-cost percentage stays editable: buyer charges vary by loan program, lender, title/settlement provider, prepaid items, escrow setup, inspections, credits and assistance. A single hard-coded percentage would create false precision.
Go from a generic estimate to property-specific intelligence
Public calculators answer the planning question. Watchdog paid plans add saved properties, deeper property intelligence, governed signals and professional workflows without changing the underlying facts to make a forecast look more certain.
See Watchdog plansCommon questions
Is this only for first-time buyers?
No. It is especially useful for a first purchase because it separates cash-to-close planning from monthly ownership cost, but the same arithmetic works for any financed home purchase.
Does the calculator include PMI or other mortgage insurance automatically?
No. Mortgage-insurance rules depend on the loan program and transaction. Enter the monthly amount from your lender when it applies.
Why include maintenance if it is not a bill?
Maintenance is not a fixed monthly charge, but excluding it makes ownership look artificially cheaper. The reserve is a planning assumption you can change or set to zero.
Is the estimate a lender quote?
No. It is an educational budgeting tool. Use lender disclosures and settlement documents for actual financing terms, cash to close and closing charges.