Should you pay cash for a house or take a mortgage?
Paying cash saves the interest and borrowing keeps the money invested, so the answer turns on whether the cash earns more after tax than the loan costs after the interest you can actually deduct.
How it works
Enter the price, down payment, loan rate and term, then your filing status, state and household income.
The calculator follows two households side by side: one pays cash, the other borrows and invests the cash it did not spend.
Each year it counts only the mortgage interest that clears the standard deduction and the $750,000 cap, and taxes the invested account at your federal and state rates.
The loan payments come out of the invested account, so the borrowing household keeps only what is left after paying the lender.
At the end of the horizon it compares what each household holds after tax and shows the difference.
Updated September 2026
Updated for the 2026 tax year. Federal brackets and standard deductions are the 2026 figures; state brackets are each state’s 2025 schedule.
A worked example
Hypothetical result
Keep the mortgage
$3.9M
After tax, year 30
Pay cash
$3.6M
Year 30
Total interest paid
$1.5M
Over the full loan term
Tax saved by the deduction
$70K
Federal, after the standard deduction
A $1.5 million home with 20% down and a 6.25% loan for 30 years, bought by a couple married filing jointly in California with $400,000 of household income. The invested cash compounds at 7% a year, the default assumption; the other fields under More detail keep their defaults.
Year
Invested account
Loan balance
Keep the mortgage
Pay cash
Difference
5
$1,152,119
$1,120,047
$1,688,203
$1,738,911
−$50,708
10
$1,086,641
$1,010,853
$1,915,538
$2,015,875
−$100,337
15
$997,039
$861,723
$2,204,267
$2,336,951
−$132,684
20
$873,547
$658,051
$2,637,204
$2,709,167
−$71,963
25
$691,230
$379,891
$3,229,454
$3,140,667
$88,787
30
$438,751
$0
$3,945,869
$3,640,894
$304,975
In this example paying cash stays ahead through year 22; keeping the mortgage pulls ahead in year 23 and leaves about $304,975 more after tax at year 30. “Keep the mortgage” is the home less the loan balance plus the invested account after the tax a sale would trigger; “Pay cash” is the home alone.
The calculator
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More detail
Follows the loan term unless set.
Hypothetical result
The two paths over time
What each household holds after tax at the end of each year. The mortgage line counts the invested account after the tax a sale would trigger.
Keep the mortgage
Pay cash
Year by year
Dollars at the end of each year. The difference is the mortgage path less the cash path.
Year
Invested account
Loan balance
Keep the mortgage
Pay cash
Difference
This piece is general education, not individual advice.
Nothing here is individual tax, legal, or investment advice, and no outcome shown is certain. Results are hypothetical, vary with each use and over time, and are not a prediction of what any account will realize. Whether borrowing or paying cash fits your situation depends on your holdings, cost basis, liquidity, and risk tolerance. Aspirean Wealth, LLC is an SEC-registered investment adviser; registration does not imply a certain level of skill or training.
Assumptions and limitations
Criteria and methodology. The calculator compares two households that hold the same cash and buy the same home. One pays the full price. The other makes the down payment, invests the rest, and pays every mortgage payment out of that investment account, with no other money coming in. Each year the account compounds at the assumed annual return you set, pays tax on its distributions at long-term capital gains rates and reinvests what is left, pays the year’s mortgage payments, and takes back the federal tax that deducting the interest saves. Federal tax uses the 2026 brackets and standard deductions ($32,200 married filing jointly, $24,150 head of household, $16,100 single, $16,100 married filing separately); state tax uses each state’s 2025 schedule and its treatment of long-term capital gains. Interest is deductible only on the first $750,000 of the loan balance (half that for a married couple filing separately), and saves tax only to the extent it lifts itemized deductions above the standard deduction. Only federal relief for the interest is counted. The 3.8% net investment income tax applies to investment income above $250,000 of income for joint filers and $200,000 for single filers and heads of household, and $125,000 for married couples filing separately. At the end, the account is valued after the tax that selling it would trigger. Both households own the same home, so its value and running costs cancel out, and property tax, insurance and closing costs are not modeled. The fields under More detail start at these values: years compared, the loan term; home appreciation, 3% a year; other itemized deductions, $0; the rate the invested account compounds at, 7% a year; the share of the account paid out as taxable distributions each year, 2%. Those last two are the assumed annual return and the distribution yield, and both are yours to set. Other itemized deductions start at $0, so state and local taxes and charitable gifts are left out unless you enter them; entering them usually makes more of the interest deductible.
Results vary. Every figure changes with each input you enter, and the same inputs would produce different figures as tax law, loan rates and markets change. The tax tables are a point in time: the 2026 federal schedules and each state’s 2025 schedule, applied unchanged to every year of the comparison with no inflation adjustment. Results vary with each use and over time.
Investments considered. The calculator does not consider, select or recommend any specific investment, fund or portfolio, and it does not use Aspirean’s portfolios. The assumed annual return is your own assumption, applied to a generic diversified portfolio held for the whole comparison. Other investments not considered may have similar or superior characteristics.
Hypothetical. The outcomes shown are hypothetical. They do not reflect actual trading or the results of any account, and they are not a prediction of what any household will hold. Real results will differ, possibly by a lot; a portfolio that falls while it is paying a mortgage can end well below the path shown.
Definitions
Opportunity cost
What the cash could have earned if it had stayed invested instead of going into the house.
Standard deduction
A flat amount every filer subtracts from income without listing expenses: for 2026, $32,200 for a married couple filing jointly, $24,150 for a head of household and $16,100 for a single filer. Mortgage interest saves tax only to the extent your itemized deductions exceed it.
Itemized deductions
Specific expenses, such as mortgage interest, state and local taxes and charitable gifts, that you list instead of taking the standard deduction when they add up to more.
Acquisition debt
A loan used to buy, build or substantially improve a main or second home. Interest on up to $750,000 of it is deductible if you itemize.
After-tax spread
The gap between what the invested cash earns after tax and what the loan costs after any deduction. Its sign largely decides which path comes out ahead.
Frequently asked questions
Is it better to pay cash for a house or take a mortgage?
Neither is better in general. Paying cash removes the interest cost and the monthly payment. Borrowing keeps the cash invested, which comes out ahead only when that money earns more after tax than the loan costs after tax. The loan rate, your bracket, how much interest you can deduct and how long you stay all move the answer. The calculator runs both paths with your numbers.
Is mortgage interest still deductible if I take the standard deduction?
No. Mortgage interest reduces tax only if you itemize, and itemizing helps only when your deductions together exceed the standard deduction for your filing status, $32,200 for a married couple filing jointly and $16,100 for a single filer in 2026. For many households a large share of the interest ends up deducting nothing. The calculator counts only the interest that clears the standard deduction.
What is the $750,000 limit on mortgage interest?
For loans taken out after December 15, 2017, interest is deductible on up to $750,000 of debt used to buy, build or substantially improve a main or second home, or half that if married filing separately. Interest on the balance above the cap is not deductible. Legislation passed in 2025 made the limit permanent. The calculator applies the $750,000 cap, halved for a married couple filing separately.
Does borrowing only make sense if the cash actually stays invested?
Yes, and that condition carries most of the weight. The case for a mortgage rests on the cash staying invested for the life of the loan, through falling markets as well as rising ones. If the money drifts into spending, or is sold in a downturn, the household has paid interest without collecting the offsetting investment result. The calculator assumes the cash stays invested throughout, so read its answer as the most borrowing can do.
Can I buy a house with cash now and take out a mortgage later?
Often, yes. Many lenders offer delayed financing, a loan placed on a home bought outright shortly after closing, which lets a cash offer compete and still frees the money afterward. Terms, limits and timing vary by lender and loan program, and whether the new loan’s interest is deductible depends on timing and on how the proceeds are used. Ask your lender and your CPA before relying on it.
Should I pay cash for a house if I am close to retirement?
It depends on where the cash would come from and what a payment would do to your income plan. Paying from a taxable account can realize gains; paying from a retirement account can push income into a higher bracket. A mortgage in retirement is a fixed draw on the portfolio in every kind of market. The calculator sizes the tax side; the income side is a planning conversation.
Meet with us
Numbers this size deserve a second set of eyes.
If a purchase would move a large share of your liquid assets, it is worth deciding where the cash comes from, and what a payment would do to your income plan, before the check is written.
