Assumable Mortgage Calculator

Compare a conventional mortgage vs assuming an existing low-rate loan side by side. Adjust the sliders and watch the savings update instantly.

Adjust Your Scenario

$
$100K$2M
%
3%40%
%
4%10%
%
1%5%
$
$50K$1M
yrs
10 yrs30 yrs
%
5%12%
Your Blended Effective Rate
3.79%
vs 6.36% conventional (weighted average of 2.75% assumed + 8.50% gap loan)

Monthly Payment Comparison

Conventional @ 6.36%
$2,663/mo
Assumable @ 2.75% + gap loan (3.79% blended)
$2,210/mo
$452less per month with an assumable

Conventional Mortgage

Interest Rate
6.36%
Term
30 years
Down Payment
5%
$22,500
Loan Amount
$427,500
Monthly P&I
$2,663
Total Paid (30yr)
$958,626
BETTER DEAL

Assumable Mortgage

Assumed Rate
2.75%
Remaining Term
25 years
Equity Gap
Home price minus remaining balance
$100,000
Assumed Loan P&I
$350,000 over 25yr
$1,615
Gap Financing (8.50%)
$77,500 second loan ยท 30yr
$596
Blended Effective Rate
3.79%
Total Monthly P&I
$2,210
Total Paid
Assumed: 25yr + Gap: 30yr
$698,903

Cash to Close Comparison

Conventional

Down Payment
5% of $450,000
$22,500
Estimated Closing Costs
~2% of loan amount
$8,550
Total Cash Needed
$31,050

Assumable

Down Payment (5% of purchase price)
5% of $450,000 purchase price
$22,500
Estimated Closing Costs
~2% of $450,000 purchase price
$9,000
Total Cash Needed
$31,500

Savings Over Time

5 Years
$27,141
paid less
10 Years
$54,283
paid less
Full Term
$259,723
total savings
Break-even point: The assumable route may cost $450 more upfront to close. At $452/mo in savings, you break even in 1 months (1 years).

Your Savings with an Assumable Mortgage

Effective rate: 3.79% vs 6.36% conventional
$452
per month
$5,428
per year
$259,723
total interest saved
Note: Even with a large equity gap, we have lenders who finance the gap with as little as 5% down on the purchase price. The gap financing is calculated above as a second loan at 8.50%. Your actual rate may vary. Closing costs are estimated at 2% of the purchase price and may differ based on your specific situation.
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See Available Homes Now

Browse 1726+ Colorado homes with assumable mortgages. Rates as low as 2.25%.

Browse Listings โ†’

How the Assumable Mortgage Calculator Works

This calculator compares two scenarios: buying a home with a brand new conventional mortgage at today's rates vs. assuming an existing low-rate mortgage from the seller. The difference between those two payments is your monthly savings.

When you assume a mortgage, you take over the seller's existing loan balance, interest rate, and remaining term. The lender approves the transfer and the loan goes into your name. It's fully legal and lender-approved. FHA and VA loans are assumable by law.

Understanding the Equity Gap

The equity gap is the difference between the home's current value and the remaining loan balance. If a home is worth $450K and the loan balance is $350K, the equity gap is $100K. That's what you need to bring to the table as the buyer.

You don't need $100K in cash, though. Most of our buyers use a combination of a small down payment (as low as 5% of the purchase price) and a second mortgage from our partner lender to cover the rest. The calculator above factors this in: it shows your assumed loan payment plus the gap financing payment as your total monthly cost.

Even with that second mortgage at a higher rate, the blended cost is almost always lower than a new conventional loan. That's the math that makes assumables work. Read our full assumable mortgage guide for a deeper breakdown of the equity gap and your options.

What Rates Are Available?

Rates on assumable properties in our Colorado inventory range from 0.65% to 5.5%, with an average around 3.38%. The lowest rates are on VA loans originated during 2020-2021. FHA loans from the same period typically carry rates in the 2.5% to 3.5% range.

We maintain a list of 1726+ assumable properties across Colorado, updated daily. Each listing includes the assumable rate, remaining balance, and estimated equity gap so you can run the numbers before you even schedule a showing.

Who Can Assume a Mortgage?

Anyone who meets the lender's credit and income requirements can assume an FHA loan. VA loans are assumable by veterans and non-veterans alike, though the seller has to agree and the seller's VA entitlement stays tied up until the loan is paid off. Learn more about VA assumptions.

The process takes 45-90 days and goes through the lender's full approval process. We handle over 90 assumption closings and work with dedicated assumption processors who keep the banks on track. Read more on our blog.