Free tool · for home buyers
True Monthly Cost of a Home Estimator
The mortgage payment is not what the house costs. Listing-site calculators stop at the payment and, at best, an estimated tax and insurance line — none of them reserve for the roof, the furnace, or the water heater. The gap that leaves is routinely large: on the worked example this tool ships with, a $2,389.22 payment sits under a $4,118.80 true monthly cost. This free estimator adds the six lines a listing-site calculator leaves out: property tax, homeowners insurance, mortgage insurance, association dues, utilities, and a maintenance reserve scaled to the home's real age and condition. Enter one home and it returns the true monthly cost, the true annual cost, and the gap between that number and the payment you were quoted. It opens pre-filled with a worked example, so you can see the shape of the answer before you type anything.
Take it with you — free, no signup
Direct download. No email, no account — just the files.
What it does
- Adds up all seven monthly lines of owning — principal and interest plus the six above — with each one's share of the total.
- Scales the maintenance reserve to the home's age and condition from a built-in lookup table, instead of guessing a flat percentage.
- Adds mortgage insurance automatically when the down payment is under 20%, and drops it when it isn't.
- Reports the gap between the true monthly cost and the mortgage payment you were quoted — the number this whole tool exists to show you.
- Opens pre-filled with a complete worked example you overwrite with a real listing's numbers.
Own it, don't rent it
Want to know whether buying beats renting — and when?
This free tool stops at the monthly cost. The full workbook keeps going: a capital replacement reserve built component by component — roof, furnace, water heater, windows, driveway — from each one's real cost and service life, the cash you need on day one, thirty years of amortization and appreciation with mortgage insurance dropping once the balance falls below 80% of the original purchase price, and a symmetric buy-versus-rent model that returns the year owning finally beats renting and checks it against how long you actually plan to stay. Seven connected tabs (Excel, Google Sheets, or LibreOffice), five guides, and printable sheets for the showing.
A one-time purchase you keep and reuse on the next house, and the one after that. No subscription, no lead form, and it works offline.
A financial planning aid, not licensed financial, tax, real-estate, or legal advice. Every figure that ships in the file is an illustrative example for a home that does not exist — prices, rates, taxes, insurance, and upkeep vary enormously by market and change constantly. Confirm what matters with your lender, a tax professional, and your own research. Free to use; please don't resell or redistribute.