The mortgage payment is not what the house costs
Type a price into any calculator on any listing site and it hands you a monthly payment. That figure is principal and interest — the money that goes to the lender. It is the smallest true component of what a house costs you, and it is the only one those calculators are built to show, because they are lead-generation tools for people who sell mortgages.
For the example home that ships in this workbook, the quoted payment is $2,389 a month. Owning the same house actually costs $4,119 a month — a gap of $1,730 nobody mentioned.
This workbook finds that number for the specific home you are looking at, then answers the harder question: how many years would you have to stay before buying actually beat renting?
The eight costs of owning
Principal and interest is barely more than half of it. The Monthly True Cost tab breaks all eight lines out, each with its share of the total and a note on why it is there:
- Principal and interest — the mortgage payment itself, and the only line that never rises on a fixed-rate loan
- Property tax — charged whether or not you have a mortgage, and in many places reassessed to your purchase price the year you buy
- Homeowners insurance — required by the lender, and rising sharply in a great many markets
- Mortgage insurance — charged while you owe more than 80% of the original purchase price, and dropped automatically once you cross that line
- HOA or condo dues — plus the special-assessment risk a thin association reserve hides
- Routine maintenance — scaled to the home’s real age and condition, not a flat 1% rule of thumb
- Capital replacement reserve — your monthly share of the roof, the furnace, and the water heater
- Utilities — including the water, sewer, and trash a landlord may cover today
What wears out, and what to set aside
The roof does not become expensive the year it leaks. It becomes expensive the day it is installed — you simply do not get the bill until later.
The Reserves & Replacements tab lists fourteen major components with a replacement cost and a service life, and turns them into what you should set aside every year. It flags what is already past due, totals what is coming within five years, and reports the cash you actually need on day one — which is not the same as your closing costs.
The year owning beats renting
Owning is never compared against nothing. It is compared against renting the same home and investing the money you did not put down.
Both paths start with exactly the same cash. The owning path converts it into equity, spends the closing costs, pays every carrying cost, and pays to sell at the end. The renting path keeps it invested and pays rent that rises every year. Each is measured the same way — what you hold at the end, minus everything you paid out of income — and the workbook finds the first year owning pulls ahead.
Then it checks that year against how long you actually plan to stay. That single comparison is the decision.
Honest about what it cannot know
Appreciation, rent growth, and investment return are unknowable. So they sit in cells you control rather than baked into a formula. Set appreciation to zero and read the break-even year again — if the decision only works when the house appreciates strongly, you are not buying a home, you are making a leveraged bet on your local market. That may still be a bet worth making. It should be one you know you are making.
The model also cannot price stability, a school district, a yard, or the relief of a payment nobody can raise. It tells you what those things cost, so you can decide whether they are worth it with your eyes open.
Own it, don’t rent it
A free online calculator wants your email and is not neutral about the answer. A blank spreadsheet means building the amortization, the reserve schedule, the opportunity-cost model, and the break-even search yourself — then checking every formula.
This is the middle ground: a structured model you own outright, that shows its work and takes nothing from you. No subscription, no lock-in, and it works just as well on the next house.
Works in Excel, Google Sheets, and LibreOffice Calc. Prefer Sheets? The download includes a one-click “Make a copy” link to a ready-made native version — no importing, nothing to rebuild.
Want to try the idea first? The free True Monthly Cost of a Home Estimator gets you the past-the-mortgage number for one home in about a minute, with no email required.
A financial planning model, not financial advice. Every figure that ships in the file is an illustrative example for a home that does not exist — prices, rates, taxes, insurance, rents, and replacement costs vary enormously by market and change constantly. This workbook is not licensed financial, tax, real-estate, or legal advice. Confirm the numbers that matter with your lender, a tax professional, and your own research.
