15-Year vs 30-Year Mortgage
Compare 15-year and 30-year mortgage terms to see which saves more money and which fits your budget.
Our Verdict: 15-year saves significantly on interest and builds equity faster, but 30-year offers lower monthly payments and flexibility. Choose based on your cash flow and financial goals.
15-Year Mortgage
✓ Pros
- Much less total interest paid
- Lower interest rate (0.5-0.75% less)
- Build equity twice as fast
- Debt-free sooner
✗ Cons
- Higher monthly payments
- Less cash flow flexibility
- Harder to qualify for
- Less money for other investments
30-Year Mortgage
✓ Pros
- Lower monthly payments
- More cash flow for investing
- Easier to qualify for
- Flexibility to pay extra when possible
✗ Cons
- Much more total interest
- Slower equity buildup
- Higher interest rate
- Debt for three decades
In-Depth Analysis
The choice between a 15-year and 30-year mortgage is fundamentally a tradeoff between cost and cash flow flexibility. The 15-year mortgage will always be cheaper in total interest cost — sometimes dramatically so. But the 30-year mortgage's lower required payment preserves cash flow that can be deployed elsewhere, including investments that may grow faster than the mortgage's interest cost. Neither answer is universally correct; the math depends on your mortgage rate, tax bracket, and alternative investment returns.
The interest savings on a 15-year mortgage are substantial. On a $400,000 mortgage at current rates (assume 6.5% for 30-year, 6.0% for 15-year): the 30-year costs approximately $510,000 in total interest; the 15-year costs approximately $207,000 in total interest — a difference of $303,000 over the life of the loans. The monthly payment difference is roughly $850/month ($2,533 vs. $3,376). That $850/month payment difference is the key variable in the decision: put that money into a mortgage or into investments?
The "invest the difference" case is compelling at current interest rates. If the $850/month extra cash flow from choosing a 30-year is invested in a diversified portfolio returning 8% annually, it grows to approximately $494,000 after 15 years — exceeding the $303,000 in additional interest paid on the 30-year. This analysis makes the 30-year look financially superior. However, this requires steel discipline to actually invest the difference rather than spend it, and assumes low-rate environments where investment returns comfortably exceed mortgage rates. When mortgage rates are high (7%+), the case for the 15-year strengthens significantly.
Risk tolerance and financial security also matter beyond the math. The 15-year mortgage forces accelerated equity building — you own more of your home faster, reducing vulnerability to being underwater if prices fall. A fully paid-off home in 15 years provides genuine financial security that a spreadsheet comparison doesn't capture. For those within 15 years of retirement who want to enter retirement debt-free, the 15-year can be deeply rational. For younger buyers with stable income, high risk tolerance, and reliable investment habits, the 30-year with disciplined investing often wins on returns. Consider a middle path: get a 30-year mortgage but make voluntary extra principal payments — you get flexibility when needed but accelerate payoff when able.
Frequently Asked Questions
On a $300,000 mortgage: 15-year at 5.75% = ~$150,000 total interest. 30-year at 6.25% = ~$365,000 total interest. The 30-year costs over twice as much in interest.