A buyout is two separate problems wearing one name
The first problem is a price. Your spouse owns a share of the equity in the house, and if you keep it you have to hand them the cash value of that share, or give up something of equal value elsewhere in the settlement. The second problem is a cash-flow test. Once you have raised that cash, usually by refinancing, you own a bigger mortgage than the marriage did, and you service it on one income instead of two.
People routinely solve the first and skip the second. A settlement that awards you the house at an agreed value is not the same thing as a lender agreeing to lend you the money to fund it, and a divorce decree does not release you from a joint mortgage — only a refinance or a formal novation does. Until the loan is in your name alone, your former spouse's credit is still on the line and any late payment you make lands on their file too, which is why decrees usually set a deadline for the refinance and a fallback of sale if it does not happen.
The calculator handles both halves in sequence: net equity, then the buyout share, then the loan that funds it, then the payment, then the ratio test.
How the equity is netted down, and why the cost of sale is contested
Gross equity is value minus mortgage. Net equity subtracts something else: what it would cost to turn the house into cash. Agent commission, transfer taxes and closing costs typically run in the region of 6% to 8% of the sale price in the United States, and the argument in almost every buyout is whether that deduction belongs in the number.
The spouse keeping the house says yes: the other party's share should be what they would actually have received had the house been sold, and the keeping spouse will bear those costs one day. The spouse leaving says no: no sale is happening, the cost is hypothetical, and deducting it transfers real money today for a cost that may never be incurred. Both arguments are made in court and neither wins universally — some jurisdictions deduct costs of sale only when a sale is imminent or ordered. Set the field to zero to see the gross-equity version and compare; on the default figures the difference is $14,700 in the buyout, which is 7% of $420,000 halved.
Once the share is priced, the loan follows. You need enough to retire the existing mortgage and to pay the buyout, less whatever cash you can bring. That new balance is then amortised at the quoted rate over the chosen term, and the payment goes into the ratio test alongside taxes, insurance, HOA dues and a realistic upkeep allowance. Lenders do not count upkeep. Include it anyway: a house does not stop needing a roof because you are divorcing.
One financing detail is worth knowing before you shop. Fannie Mae treats a refinance that buys out a co-owner's interest under a written agreement as a limited cash-out refinance rather than a cash-out refinance, even though cash is leaving the transaction. That classification matters, because cash-out refinances carry tighter loan-to-value limits and worse pricing. Bring the decree or the settlement agreement to the lender and make sure the transaction is coded correctly.
Worked example: a $420,000 house with $250,000 owing
The house appraises at $420,000. The mortgage payoff is $250,000. The settlement gives your spouse half the net equity and you assume a 7% cost of sale. You have $10,000 in cash to contribute, you are quoted 6.5% on a 30-year refinance, tax, insurance and HOA run $6,450 a year, and you budget 1% of value a year for upkeep. Your income after support is $10,200 a month and you carry $600 a month in other debt.
- Selling costs. 7% × $420,000 = $29,400.
- Net equity. $420,000 − $250,000 − $29,400 = $140,600.
- Buyout. 50% × $140,600 = $70,300.
- New loan. $250,000 + $70,300 − $10,000 = $310,300.
- Payment. At 6.5% over 30 years the factor is 6.32068 per $1,000, so 310.3 × 6.32068 = $1,961.31 a month in principal and interest.
- Carrying costs. $6,450 ÷ 12 = $537.50, plus 1% × $420,000 = $4,200 a year, which is $350 a month. Together $887.50.
- Total housing cost. $1,961.31 + $887.50 = $2,848.81.
- Front-end ratio. $2,848.81 ÷ $10,200 = 27.93%, just inside the 28% guideline.
- Back-end ratio. ($2,848.81 + $600) ÷ $10,200 = 33.81%, comfortably inside 43%.
Loan-to-value is $310,300 ÷ $420,000 = 73.88%, which keeps you clear of mortgage insurance. This deal works — but only just on the housing ratio. Half a point of extra rate pushes the payment to about $2,065 and the front-end ratio past 28%, which is exactly the kind of sensitivity the rate table below is for.
How to read the result
Look at the two ratios before you look at the buyout figure. The buyout is negotiable; physics is not. If the front-end ratio comes out above your limit, the house is unaffordable at that loan size, and the fixes are limited: bring more cash, negotiate a smaller share, take a longer term, or sell. Extending from 15 years to 30 cuts the payment substantially, but it also means you are still paying for this house well past the age at which you had planned to stop.
The largest-loan output tells you how much room you have. Compare it against the new loan: the difference is your margin. A margin of a few thousand dollars means a rate move between now and closing can undo the plan, so lock the rate rather than assuming today's quote.
Then look at loan-to-value. Above 80% on a conventional loan you will pay mortgage insurance, which this calculator does not add to the housing cost, so your real ratio is worse than shown. Above 97% no conventional programme will write the loan at all, and the buyout has to be funded from other assets or the house has to be sold.
Finally, remember what the number leaves out. It does not include the tax basis you are inheriting along with the house, and it does not include the transaction cost you will pay when you eventually sell. A house awarded at $420,000 with a $90,000 basis carries a latent capital gains liability that a retirement account of the same nominal value does not, which is why matching a house against a 401(k) dollar for dollar usually favours whoever takes the account. Run the home sale capital gains tax calculator on the eventual sale before you agree that the two assets are equal.
Buyout share against equity: what you have to raise
| Net equity | 40% share | 50% share | 60% share |
|---|---|---|---|
| $100,000 | $40,000 | $50,000 | $60,000 |
| $150,000 | $60,000 | $75,000 | $90,000 |
| $200,000 | $80,000 | $100,000 | $120,000 |
| $250,000 | $100,000 | $125,000 | $150,000 |
| $300,000 | $120,000 | $150,000 | $180,000 |
Net equity is value minus mortgage minus any cost of sale you deduct. Add the mortgage balance to the cell to get the loan you have to qualify for.
What goes wrong in a house buyout
- Using the tax assessment as the value. Assessments lag the market and are computed for a different purpose. Get an appraisal, and if the two of you cannot agree, agree on a single appraiser in advance rather than duelling reports.
- Assuming the decree removes you from the loan. It does not. Only a refinance, a formal assumption approved by the lender, or a sale takes a name off the note. Set a deadline in the agreement and a consequence if it is missed.
- Forgetting that the payment now sits on one income. Two salaries carried the old mortgage; one carries a bigger new one. This is the single most common reason a buyout unwinds within two years.
- Ignoring mortgage insurance above 80% LTV. It can add a meaningful monthly sum that is absent from every quote you were shown as principal and interest.
- Trading the house against a retirement account at face value. A house carries selling costs and a deferred capital gain; a Roth account carries neither. Compare after-tax, after-cost values.
- Overlooking the deferred maintenance. The roof, the furnace and the water heater are on their own clock and do not care about the settlement date. The upkeep allowance in this calculator exists for a reason.
Where the buyout sits in the wider settlement
Fix the income figure before you fix the house. Support runs first: the child support estimate calculator and the alimony and spousal support calculator both change the income you enter here, in one direction if you receive and the other if you pay. Then the buyout becomes one line in the overall division — the marital property division calculator shows how an equalising payment can be routed through the house rather than through cash, which is often cleaner than a refinance.
If you conclude the house does not work, the alternatives are worth pricing rather than dreading. Selling and splitting the proceeds is the simplest and cheapest, because it converts a contested value into an actual number and removes both names from the loan on the same day. Deferred sale — one spouse stays until a trigger such as the youngest child finishing school, then the house is sold and the proceeds divided — keeps stability at the cost of leaving both parties financially entangled for years.
Whatever route you take, sanity-check the payment against a plain mortgage payment calculator and your overall borrowing capacity against a home affordability calculator run on your post-divorce income. If those two disagree with this page, the difference is almost always mortgage insurance or an escrow figure you have not yet updated.
Ratios are guidelines, not laws
The 28% housing and 43% total-debt figures used as defaults here are conventional underwriting conventions; 43% is the general qualified-mortgage threshold under the ability-to-repay rule. Individual programmes go higher with compensating factors such as large reserves or a high credit score, and FHA and VA use their own limits. Set the two limit fields to whatever your lender has told you, and treat anything above them as a signal to re-plan rather than as a verdict.