Free tools / 15 vs 30 year mortgage calculator
15 vs 30 Year Mortgage Calculator
Compare a 15-year and 30-year loan side by side — the monthly payment, the total interest, and when the house is paid off — then see the honest answer to "which is actually better" once you account for investing the difference. Free, no signup.
Your loan
Home price minus your down payment
15-year rates run lower than 30-year
These are principal & interest only — property tax, insurance, and any HOA are the same under either term, so they don't change the comparison.
15-year mortgage
$2,989/mo
- Total interest
- $178,106
- Total paid
- $538,106
- Paid off in
- 15 years
30-year mortgage
$2,275/mo
- Total interest
- $459,160
- Total paid
- $819,160
- Paid off in
- 30 years
The trade-off
The 15-year costs $714 more each month, but saves $281,054 in interest and pays the house off 15 years sooner.
But what if you invest the difference?
The 15-year's interest savings are guaranteed. The 30-year's lower payment frees up cash you could invest instead — and the market might beat your mortgage rate. On the same monthly budget (the 15-year payment), here's where each path lands after 30 years:
15-year, then invest — wins
$947,551
Invest the full payment for years 16–30, once the house is paid off.
30-year, invest the gap
$871,098
Invest $714/month for all 30 years.
At a 7% return, the 15-year path comes out about $76,454 ahead — but flip the return rate and the winner flips too. The wider the gap between your return and the 30-year rate, the more the 30-year wins; the smaller it is, the more the guaranteed 15-year savings win. Both paths assume you actually invest the difference every month — the 15-year's savings are automatic, while investing takes discipline.
Work in real estate? The people running this math are planning a move.
Reach homeowners before they list — draw any neighborhood on WhoseTitle and get every owner inside it, with tenure and likelihood-to-sell signals, free from public county records.
Start finding leads — freeHow to use the 15 vs 30 calculator, step by step
- 1
Enter the loan amount
The amount you're actually borrowing — the home price minus your down payment, not the price itself.
- 2
Enter both interest rates
Use the rate a lender quotes for each term. The 15-year rate is normally about half a point lower than the 30-year — enter what you're actually offered, since that gap is a big part of the story.
- 3
Read the two cards
Each shows the monthly payment, the total interest over the life of the loan, the total paid, and the payoff date. The one-line trade-off underneath sums up the difference in plain terms.
- 4
Test the "invest the difference" scenario
Set the return you think you could earn investing, and the calculator shows where each path lands after 30 years on the same budget. Slide the return up and down and watch the winner change — that sensitivity is the real insight.
The 15-year and 30-year trade-off
The same loan can be repaid over 15 years or 30, and the choice shapes your finances for decades. The 15-year path demands a bigger monthly payment but hands you a lower interest rate, a paid-off house in half the time, and dramatically less interest. The 30-year path keeps your required payment low and your monthly budget flexible, at the cost of far more interest and a much slower climb to owning the home outright.
15-year: higher payment, less interest, faster equity
30-year: lower payment, more interest, more flexibility
An example, start to finish
Take a $360,000 loan. At a 5.75% 15-year rate, the payment is about $2,989 a month, and you'll pay roughly $178,000 in interest before the house is yours in 2041. At a 6.5% 30-year rate, the payment drops to about $2,275 — $714 less each month — but you'll pay around $459,000 in interest and not own the home outright until 2056.
So the 15-year costs $714 more a month and saves about $281,000 in interest. Framed that way it looks like an easy win — until you ask what that extra $714 a month could do somewhere else. That's the question the next section answers.
The honest answer: invest the difference
Here's the argument financial planners actually have. The 15-year's interest savings are real and guaranteed. But the 30-year's lower payment frees up $714 a month, and if you invest that money and earn more than your mortgage rate, you can end up wealthier — even while paying more interest.
The calculator compares both paths on the same budget: whether you send the money to the bank as a bigger payment, or to the market as an investment. When your expected return sits well above the 30-year rate, the 30-year-and-invest path tends to win. When the gap is thin — or when you doubt you'd actually invest the difference every single month — the guaranteed 15-year savings win. There's no universal answer, only your numbers and your discipline. The 15-year forces the saving; the 30-year merely allows it.
Helping a client choose a mortgage?
WhoseTitle helps agents find the clients in the first place — draw any neighborhood and get every owner inside it, with tenure and likelihood-to-sell signals, free from public county records.
15 vs 30 year FAQs
Is a 15-year or 30-year mortgage better?
Neither is universally better — it's a trade-off. A 15-year loan has a higher monthly payment but a lower rate, far less total interest, and builds equity fast. A 30-year loan has a lower, more flexible payment but costs much more interest over its life. The right answer depends on your cash flow, your discipline, and what return you could earn investing the monthly difference instead.
Why is the 15-year interest rate lower?
Lenders take less risk over 15 years than 30, and they get their money back sooner, so they charge less for it — typically 0.5% to 0.75% below the 30-year rate. That lower rate, combined with the shorter term, is why the total interest on a 15-year loan is often less than half the 30-year figure.
How much more is a 15-year payment?
Usually 40–50% higher per month than the 30-year payment on the same loan, because you're compressing repayment into half the time. The calculator shows the exact dollar gap for your numbers. That higher payment is the whole catch: it's a forced savings plan that not every budget can absorb.
Should I take a 30-year and invest the difference?
It can beat the 15-year — if you actually invest the monthly difference every month and your after-tax return exceeds the 30-year rate over the long run. Historically a diversified stock index has returned around 7%, above typical mortgage rates, which favors the 30-year-and-invest path. The catches: market returns aren't guaranteed, and most people spend the difference rather than invest it, while the 15-year's savings are automatic. The calculator runs both paths so you can see how sensitive the answer is to the return you assume.
Can I just pay extra on a 30-year to pay it off in 15?
Yes, and it's a popular middle path: take the 30-year for the flexibility of a low required payment, then voluntarily pay it down faster. You'll pay the 30-year's higher rate rather than the lower 15-year rate, so you save a bit less interest than a true 15-year — but you keep the option to drop back to the smaller payment in a tight month, which a 15-year doesn't give you.
Does the comparison include taxes and insurance?
No, and it shouldn't. Property taxes, homeowner's insurance, and any HOA dues are the same whether you choose a 15- or 30-year loan, so they don't affect the comparison. This calculator shows principal and interest only — the part of the payment that actually differs between the two terms.