15-Year vs 30-Year Mortgage Calculator
Compare a 15-year and 30-year mortgage on the same loan: monthly payment difference and total interest saved. Runs in your browser.
15-year vs 30-year
| 15-year | 30-year | |
|---|---|---|
| Monthly payment | $2,906 | $2,212 |
| Total interest | $173,158 | $446,406 |
| Total paid | $523,158 | $796,406 |
15-year loans have lower rates and far less total interest, but a higher monthly payment. The 30-year frees up cash flow you could invest — if your expected investment return beats the rate spread, the 30-year can win financially, though the 15-year is the guaranteed, forced-savings choice. Informational, not financial advice.
About this tool
The choice between a 15-year and 30-year mortgage is one of the biggest financial decisions a homebuyer makes, and this calculator lays out the trade-off clearly. For the same loan amount, it computes the monthly payment and total lifetime interest for each term, using the (usually lower) 15-year rate and the 30-year rate. The 15-year wins dramatically on total interest — often less than half what a 30-year costs — because you borrow for half as long and at a lower rate, and it builds equity far faster. The cost is a substantially higher monthly payment. The 30-year's appeal is cash-flow flexibility: the lower required payment frees money you could invest, and if your expected investment return exceeds the mortgage rate, the 30-year can come out ahead financially while letting you prepay voluntarily in good years. The 15-year, by contrast, is a guaranteed return equal to its rate and a form of forced savings. There is no universally right answer — it depends on your income stability, discipline, and other goals. It is informational, not financial advice. Everything runs in your browser.
How to use it
- Enter the loan amount.
- Enter the 15-year and 30-year interest rates (15-year is usually lower).
- Compare the monthly payments and total interest.
- Weigh the interest savings against the cash flow you'd free up to invest.
Frequently asked questions
- How much interest does a 15-year save?
- Often more than half versus a 30-year, because you pay interest for 15 years instead of 30 and typically at a lower rate. On a large loan that can be a six-figure difference, which the calculator quantifies for your numbers.
- Why is the 15-year monthly payment so much higher?
- You repay the same principal in half the time, so each payment includes much more principal. The payment is usually well under double the 30-year (the lower rate and interest savings help), but it is a significant jump that must fit your budget.
- Is a 15-year always the better choice?
- Not necessarily. It saves interest and builds equity fast, but the higher payment reduces flexibility. A disciplined borrower might take a 30-year, invest the payment difference, and come out ahead if returns beat the rate — while keeping the option to pay less in a tight month.
- Why are 15-year rates lower?
- Lenders take on less interest-rate and default risk over a shorter term, so they offer a lower rate — commonly 0.5–0.75 percentage points below the 30-year. That rate gap adds to the 15-year's interest savings.
- Can I get 15-year results on a 30-year loan?
- Effectively yes — take the 30-year for payment flexibility and voluntarily pay extra principal to mimic a 15-year payoff. You keep the lower required payment as a safety net but capture much of the interest savings when you can afford to.
- Is this financial advice?
- No. It is an informational comparison. Consider your full finances or consult an advisor.