Buy Before You Sell Calculator

Q: Will the lender count both mortgage payments?

It may. Treatment depends on the pending sale, title-transfer timing, contract documentation, cleared contingencies, and loan program.

Q: Is a HELOC the same as a bridge loan?

No. A HELOC is a revolving line secured by the current home, while bridge financing is short-term transition financing. Terms and underwriting vary.

Q: Does this include capital-gains tax?

No. Tax treatment depends on individual facts and requires advice from a qualified tax professional.

The timing decision

You are not comparing one mortgage with another.

You are comparing two sequences. Buying first may reduce moving disruption but can create a short period with several obligations. Selling first may lower financing pressure but can create temporary housing, storage, and a second move.

01 · Cash

Can the purchase close?

We compare your usable savings and cautious equity access with the down payment and buyer costs.

02 · Carry

What peaks before the sale?

We show the current home payment, new housing payment, and bridge interest together.

03 · Timing

What does each sequence add?

We compare buy-first overlap costs with temporary housing, storage, and the extra move.

First, let’s estimate the equity that exists—not the amount you can automatically borrow.

Step 1 · Your current home

What could be left when this home sells?

Home value is not cash. The mortgage, liens, selling expenses, and adjustments have to come out before the remaining proceeds can support the move.

Expected current-home sale price

Use a realistic market estimate—not the tax assessment.

Mortgage payoff and other liens

Use the expected payoff, including other loans secured by the home.

Selling-cost planning rate

Editable placeholder for compensation, settlement, taxes, HOA, and contract-related items.

Other sale deductions

Repairs, concessions, preparation costs, or another known deduction.

Liquid cash savings

Cash you could document and potentially use before the sale.

Cash you want to protect

This amount stays outside the modeled purchase cash.

Estimated sale proceeds before bridge repayment

Usable savings after reserve

Why available equity is not the same as sale proceeds

A lender may limit borrowing to a percentage of the home’s value, order an appraisal, subtract existing liens, require reserves, and apply product-specific underwriting. The sale proceeds occur later and must also repay any bridge balance that used the same equity.

Now we build the cash and payment side of the next purchase.

Step 2 · Your next home

How much has to be ready before your sale closes?

The down payment and buyer closing costs create the immediate cash target. The mortgage, taxes, insurance, HOA, and possible PMI create the ongoing payment.

Expected next-home price

Target down payment

You can type an exact percentage. This is a target, not a lender requirement.

Buyer closing-cost planning rate

Use the detailed buyer calculator or lender estimate when available.

New mortgage rate scenario

Planning scenario only—not a current quote.

New mortgage term

Property-tax planning localityFairfax County · FY 2027 base planning rate; reviewed August 2026.

Annual property-tax rate

Annual homeowners insurance

Monthly HOA or condo dues

Annual PMI planning rate

Applied only when the modeled down payment is below 20%.

Purchase cash needed before the sale

New mortgage amount

Estimated new monthly housing cost

What is inside the monthly estimate?

Principal and interest, base property tax, entered insurance, HOA or condo dues, and planning PMI when the down payment is below 20%. It does not replace a Loan Estimate or property-specific insurance and tax records.

This section is a stress test. The lender—not this page—decides what equity can be accessed and whether you can carry the overlap.

Step 3 · Buy-first scenario

What happens if the next purchase closes first?

We use a cautious, editable combined-loan-to-value placeholder. The calculation borrows only what the purchase cash needs and never counts the same bridge proceeds twice.

Maximum combined loan-to-value assumption

A planning ceiling, not a product promise. Actual programs vary.

Bridge annual interest-rate assumption

Editable placeholder. Use the lender’s written disclosure.

Bridge fee assumption

Planning placeholder for lender/origination costs.

Current monthly housing payment

Current principal, interest, taxes, insurance, and HOA/condo dues.

Expected overlap before the sale pays off

Longer-sale stress test

Maximum modeled bridge capacity

Bridge amount actually needed

Purchase cash gap before sale

Peak monthly obligations during overlap

Why a lender may still count both homes

Fannie Mae guidance says the current and proposed housing payments may both be used when the current residence is pending sale but will not transfer before the new purchase, unless specified contract and financing-contingency documentation supports different treatment. Your lender must review the exact file.

Why bridge interest may not reduce the balance

Some short-term loans are interest-only or accrue interest until payoff. Interest-only payments do not reduce principal, and balloon features can require a large payoff. Use the actual written terms instead of assuming every bridge works the same way.

Now we price the inconvenience of selling first so the comparison is fair.

Step 4 · Sell-first alternative

What would temporary housing and a second move cost?

Selling first can reduce financing uncertainty, but temporary rent, storage, pet fees, deposits, and another move are real costs. Enter what your household would actually face.

Temporary housing per month

Temporary-housing months

Storage per month

Extra move and setup cost

Estimated sell-first transition cost

Planned buy-first timing cost

Longer-sale stress cost

What is excluded from this comparison?

The ordinary new-home payment is visible in the peak-obligation result but excluded from the timing-cost comparison because it continues after the move and is not created solely by the sequence. Taxes, tax benefits, rate locks, appraisal changes, and contract acceptance are not modeled.

Here is the worksheet I would use to decide what needs a lender quote and what needs a property-specific sale plan.

Your planning result

Your timing plan, in one view

Purchase cash needed before sale

Usable savings

Modeled bridge

Buy-first funding gap

Peak monthly obligations

Planned buy-first timing cost

Sell-first transition cost

Sale proceeds remaining after bridge payoff

This result tests cash flow and timing. It is not an approval, commitment, appraisal, rate quote, or promise that a seller will accept an offer without a home-sale contingency.

Timing-cost comparison

How the added costs change if the sale takes longer

The green buy-first cost grows with each month of current-home payment and bridge interest. The orange sell-first estimate uses the temporary-housing assumptions you entered.

Buy firstSell first

Incremental timing-cost comparison at one, three, six, and selected overlap months.

View the accessible timing-cost table

Overlap	Buy-first timing cost	Sell-first transition estimate

Change one answer without starting over

Edit current home Edit next home Edit buy-first assumptions Edit sell-first costs

Keep this estimate privately. Print or save a PDF, or download a plain-text summary. Nothing is submitted unless you choose a review.

No cost · No obligation

Want to review the actual homes and timing?

I can prepare the current-home market analysis, discuss the next-home target, and identify which numbers need written lender or settlement quotes.

Schedule a review with Abraham

Common questions

What I would want you to understand before choosing the sequence

Is this a bridge-loan approval?

No. It is an educational cash-flow model. A lender evaluates income, debts, credit, assets, reserves, appraisal, lien position, occupancy, program rules, and documentation.

Will the lender count both mortgage payments?

It may. The treatment depends on whether your current home is pending sale, when title will transfer, the executed contract, cleared financing contingencies, and the loan program. Fannie Mae’s published guidance is linked below, but your lender must apply the current rules to your file.

Is a HELOC the same as a bridge loan?

No. A HELOC is a revolving line secured by the current home and commonly has a variable rate. A bridge or swing loan is short-term financing structured for a transition. Fees, payment structures, access limits, lien positions, and underwriting vary.

Why does the calculator subtract the bridge from later sale proceeds?

The bridge used equity before the sale. Subtracting it later prevents the same equity from appearing once as purchase cash and again as untouched sale proceeds.

What if the current home sells for less?

Lower the expected sale price with the adjustment control. The model will reduce bridge capacity and later proceeds. A lower appraisal can also affect borrowing capacity before the sale.

Does a home-sale contingency solve the cash problem?

It can align the transactions, but it does not automatically make the offer acceptable or remove all timing risk. Contract terms, market conditions, current-home status, and the seller’s alternatives matter.

What about a rent-back?

A post-settlement occupancy agreement may reduce temporary-housing pressure after your sale, but its availability, duration, deposit, insurance, and lender requirements are contractual and property-specific.

Does this include capital-gains tax or tax deductions?

No. Tax treatment depends on individual facts and cannot be responsibly inferred from these inputs. Ask a qualified tax adviser.

Sources and calculation notes

How this estimate is built

The engine estimates sale proceeds, protects the reserve you enter, limits modeled bridge funds to an editable combined-loan-to-value ceiling, uses only the bridge amount needed for the purchase cash, calculates interest and fees, and subtracts the bridge from later sale proceeds. All public rate and program inputs are planning assumptions until replaced with written quotes.

Planning assumptions last reviewed: August 14, 2026. Next review: September 2026.

Educational planning estimate only. Confirm qualification, loan terms, values, timing, settlement charges, insurance, tax treatment, and contract strategy with the appropriate licensed professionals and property-specific records.

Can you buy your next home before this one sells?