True Cost of Homeownership Calculator — What a House Actually Costs Per Month
Your mortgage quote is about two-thirds of the real number — see all four cash costs in one place
Reviewed for accuracy August 31, 2026 by Gary S.
Annual, as % of home value. Defaults to 1.2%; the national average is ≈1.1% and real rates run 0.5–2.5% by metro
Annual, as % of home value. 1.5% covers routine upkeep plus the major-repair cycle; 1% if you budget repairs separately
Leave at 0 if none
Optional — used to check the 28% housing guideline
$3,126/month is 31% of gross income — above the 28% guideline
True housing cost is $3,126 against $10,000/month gross. That clears the 36% back-end limit but sits above the 28% front-end guideline, and the mortgage quote of $2,076 understates it by 51%.
- ›Principal & interest is only 66% of the true monthly cost — $1,050/month sits outside your mortgage quote
- ›Every 0.1% of property tax on a $400,000 home is $33/month — check your county rate rather than the national 1.1% average
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How to use True Cost of Homeownership Calculator
Free true cost of homeownership calculator. Add property tax, insurance, maintenance and HOA to your mortgage P&I to see the real monthly and annual cost of owning a home.
What is the true cost of homeownership?
The true cost of homeownership is your mortgage principal and interest plus property tax, homeowner’s insurance, maintenance and any HOA dues — which together typically add roughly 50% on top of the mortgage payment, meaning principal and interest is only about two-thirds of what the house actually costs each month.
| Cost line | Monthly on a $400,000 home | Basis |
|---|---|---|
| Principal & interest | $2,076 | $320,000 at 6.75%, 30 years |
| Property tax | $400 | 1.2%/yr — ranges 0.5–2.5% by metro |
| Homeowner’s insurance | $150 | 0.45%/yr, standard coverage |
| Maintenance | $500 | 1.5%/yr of home value |
| True cost | $3,126 | P&I is 66% of it — budget +51% |
A mortgage quote tells you the principal and interest payment. It does not tell you what the house costs. Property tax, homeowner’s insurance, maintenance and HOA dues are all recurring, all unavoidable, and none of them appear in the number a lender quotes you. This calculator adds the four cash costs together so you can see the real monthly and annual figure before you commit — and shows what share of it the mortgage payment actually represents, which for most buyers is around two-thirds.
How to use this True Cost of Homeownership Calculator
- 1Enter the home price and your planned down payment. The loan amount is the difference.
- 2Enter the mortgage interest rate and pick a term — 30 years is standard, 15 raises the payment but cuts total interest.
- 3Set the property tax rate for the county you are buying in. The field defaults to 1.2%; the national average is about 1.1% and real rates run from roughly 0.5% to 2.5%, making this the single largest source of variation between metros.
- 4Set a maintenance rate. 1.5% of home value per year covers routine upkeep plus the major-repair cycle; use 1% if you budget roof and HVAC replacement separately, or 2% for older homes in harsh climates.
- 5Add monthly HOA dues if the property has them, and your gross annual income to check the result against the 28% housing guideline.
- 6Read the true cost per month, the share of it that is principal and interest, and the annual figure.
True cost of homeownership formula
Principal and interest is fixed by the loan, but the other three lines scale with the home’s value, not the loan — which is why a larger down payment lowers P&I without reducing tax, insurance or maintenance at all. Insurance is applied at 0.45% of home value per year, the national-average rate this site uses throughout.
| Variable | Meaning |
|---|---|
| P&I | Principal and interest on the loan amount (price minus down payment) |
| Tax rate | Annual property tax as a percentage of home value — defaults to 1.2%, national average 1.1% |
| Insurance | 0.45% of home value per year, standard coverage |
| Maintenance rate | Annual upkeep as a percentage of home value — 1.5% default, 1% routine-only, up to 2% for older homes |
| HOA | Monthly association dues, where applicable — buys no equity |
True cost example: $400,000 home, 20% down, 6.75% rate
- 01Home price $400,000 with $80,000 down leaves a $320,000 loan.
- 02P&I at 6.75% over 30 years: $2,076/month.
- 03Property tax at 1.2%: $4,800/year = $400/month.
- 04Insurance at 0.45%: $1,800/year = $150/month.
- 05Maintenance at 1.5%: $6,000/year = $500/month.
- 06True cost: $2,076 + $400 + $150 + $500 = $3,126/month, or $37,506/year.
Result
The mortgage quote of $2,076 is 66% of the real monthly cost of $3,126 — so budget roughly 51% on top of any P&I figure you are quoted. On a $120,000 income that is 31% of gross, above the 28% housing guideline.
What affects your true cost of homeownership?
Property tax rate
The largest source of variation between markets. At 0.5% a $400,000 home costs $167/month in tax; at 2.5% it is $833/month — a $666/month swing on the identical house. Always use the actual county rate, never the national average, when comparing metros.
Age and condition of the home
The 1% maintenance rule assumes a reasonably modern home in reasonable repair. Older properties, and anything with an aging roof or HVAC system, justify 1.5–2%. Maintenance you defer does not disappear — it accumulates into a larger bill later.
Down payment does not reduce three of four lines
A larger down payment lowers principal and interest only. Property tax, insurance and maintenance all scale with the value of the home, so they are unchanged whether you put down 5% or 50%.
HOA dues
HOA fees buy services, not equity, and they rise over time. A $300/month HOA is $3,600/year of spending that builds no ownership stake, and it is fully within the housing ratio lenders assess.
Tips and things to know
- ✓Budget from the true cost figure, not the mortgage quote — the gap between them is roughly 50% for most homes.
- ✓Get the actual property tax rate from the county assessor before making an offer; a two-point swing in tax rate can outweigh a half-point swing in mortgage rate.
- ✓Hold the maintenance figure in a separate account rather than treating it as slack in the monthly budget. It is not optional spending, it is deferred spending.
- ✓Re-run this with a 15-year term to see how much of the true cost is interest rather than ownership.
True Cost of Homeownership Calculator — bottom line
The gap between a mortgage quote and the real cost of a house is the single most common budgeting error in home buying, and it is structural rather than careless: the number a lender quotes is the number a lender cares about, and a lender does not care what your roof costs. On a $400,000 home the quoted $2,076 becomes $3,126 once tax, insurance and maintenance are included — an extra $1,050 a month, or $12,600 a year, that has to come from somewhere. The second error is treating maintenance as optional because it is irregular. Nothing breaks in most months, which makes the 1% rule feel like an overestimate right up until the year the HVAC and the roof both fail. Averaged across a decade of ownership the rule is close to right, and the money is far easier to find in a dedicated account than in a single month’s budget. Use this calculator before making an offer, not after: the difference between a 0.8% and a 1.9% property tax rate is larger than most buyers’ entire negotiating range on price.
Official resources and further reading
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Frequently asked questions
Mortgage principal and interest plus property tax, homeowner’s insurance, maintenance and any HOA dues. On a $400,000 home with $320,000 financed at 6.75%, that is $3,126/month against a $2,076 mortgage payment — principal and interest is about 66% of the real cost, so budget roughly 51% on top of any quote.
From our guides
All guides →The Hidden Opportunity Cost of a 20% Down Payment
On a $400,000 home at 6.5%, putting 10% down and investing the other $40,000 at 7% wins by only $5,436 over ten years — after PMI, higher payments, and a larger remaining balance. At 8% the trade turns negative.
What Salary Do I Need for a $400K House? The Exact Math (2026)
You need about $109,000/year for a $400,000 house with 20% down at 6.5% (28% DTI standard; $2,539 PITI). With 10% down it rises to ~$126,000; with $1,000/mo of debts, ~$118,000. Full breakdown with rate sensitivity.
How to Calculate Home Affordability: The 4 Rules Lenders Use
Home affordability is calculated using four ratios: the 28% front-end rule, the 36% back-end rule, the 43% DTI ceiling, and the 3x–5x income rule. Most buyers are constrained by their back-end DTI, not their income. A worked example shows exactly what you can borrow at $90,000 gross income with $500/month in existing debt.
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