Half a Century of Debt? Here’s What a 50-Year Mortgage Would Cost You
President Donald Trump recently floated the possibility of a 50-year mortgage.
A 50-year mortgage would mean lower monthly payments for homebuyers, which would certainly be appealing for those who feel priced out of the market. However, there are also some very real downsides. In exchange for that lower payment, homeowners would likely face a higher interest rate, pay significantly more interest over the life of the loan and build equity more slowly than they would with shorter-term mortgages.
Breaking down monthly payments, interest paid
A 50-year mortgage would likely come with a higher interest rate than a 30-year mortgage, though it’s impossible to know how much higher. However, even if the 50-year mortgage came with the same APR as the 30-year, the math would look quite different.
Here’s a look at the differences in costs for a 50-year mortgage versus a 30-year mortgage on a $500,000 loan with a 6.10% APR — roughly the average current rate for a 30-year, fixed-rate mortgage today.
Monthly payments and total interest paid on a $500,000 loan with a 6.10% APR
| Loan term | Monthly payment | Total interest paid | % of original balance paid in interest |
|---|---|---|---|
| 50 years | $2,669 | $1,101,430 | 220.29% |
| 30 years | $3,030 | $590,791 | 118.16% |
| 15 years | $4,246 | $264,342 | 52.87% |
With a 50-year mortgage, the amount you’d pay in interest in this example would total more than double the original purchase price of the home — a staggering $1.1 million-plus in interest. With a 30-year mortgage, you’d still pay an enormous amount of interest, but nearly half of what you’d pay on a 50-year mortgage. Not surprisingly, the total interest paid on a 15-year mortgage is far lower, though it comes with a much higher monthly payment.
Here’s what it would look like if you increased the APR to 7.00%, roughly the average rate at the start of 2025.
Monthly payments and total interest paid on a $500,000 loan with a 7.00% APR
| Loan term | Monthly payment | Total interest paid | % of original balance paid in interest |
|---|---|---|---|
| 50 years | $3,008 | $1,305,065 | 261.01% |
| 30 years | $3,326 | $697,544 | 139.51% |
| 15 years | $4,494 | $308,945 | 61.79% |
With this higher APR, the interest you’d pay on a 50-year mortgage would equal more than two-and-a-half times the original balance — more than $1.3 million in total.
Finally, here’s a look at what would happen if rates fell to 4.00%, significantly lower than today’s rates but higher than the record low rates seen at the start of the decade.
Monthly payments and total interest paid on a $500,000 loan with a 4.00% APR
| Loan term | Monthly payment | Total interest paid | % of original balance paid in interest |
|---|---|---|---|
| 50 years | $1,929 | $657,121 | 131.42% |
| 30 years | $2,387 | $359,348 | 71.87% |
| 15 years | $3,698 | $165,719 | 33.14% |
Even with these lower rates, you’d still pay $657,121 in interest over 50 years, well more than the original $500,000 balance.
50-year mortgage would mean slower equity growth
With any mortgage, your early years are spent paying more toward interest than to the original loan balance. That means that the equity in your home tends to grow slowly. That is certainly true with a 30-year mortgage, but it’s even more apparent with a 50-year mortgage.
Here’s what that looks like, using the same $500,000 loan and 6.10% APR as the first example.
Timeline for paying off original loan balance on $500,000 mortgage with 6.10% APR
| 50-year mortgage | 30-year mortgage | |||
|---|---|---|---|---|
| Time | Amount of original balance paid off | % of original balance | Amount of original balance paid off | % of original balance |
| 10 years | $20,989 | 4.20% | $80,459 | 16.09% |
| 20 years | $59,559 | 11.91% | $228,310 | 45.66% |
| 30 years | $130,433 | 26.09% | $500,000 | 100.00% |
| 40 years | $260,673 | 52.13% | Not applicable | Not applicable |
| 50 years | $500,000 | 100.00% | Not applicable | Not applicable |
After 10 years of paying on that 50-year mortgage, you’d have only paid about $21,000 on the original $500,000 balance — just over 4%. Compare that to the 30-year mortgage, with which you would’ve paid more than $80,000, or 16%, of the original balance.
Looking out 20 years, the difference is even more stark. With a 30-year mortgage, you’ve paid about $228,000 — nearly half the original balance. With a 50-year mortgage, you’d have paid off about $60,000, or 12%, of the original balance.
That’s a significant development because home equity can be a powerful asset. A 50-year mortgage means that equity will take far longer to grow. It also creates a real risk because it means that a homeowner could more easily be underwater on a loan — meaning they owe more on the house than the house is worth — in the event of a downturn in the housing market. That’s a troubling spot to be in.
Understand what’s right for you
The future of the 50-year mortgage is unclear. However, there’s plenty that home shoppers can do today to lower their mortgage costs, regardless of what comes of the 50-year mortgage.
One of the most impactful pieces of advice is also the simplest: Shop around. You can compare rates from multiple lenders before you apply for a loan. Recent LendingTree research shows that the savings can be massive:
- November 2025: “Refinancing at the best available rate could save you $50,000 or more over your current mortgage.”
- June 2025: “Borrowers could save an average of $80,024 over the life of a 30-year, fixed-rate mortgage by shopping around.”
Those are substantial savings that can have a real impact on people’s finances, but only if you take action.