15-Year vs 30-Year Mortgage: Which Saves You More?

15-Year vs 30-Year Mortgage: Side-by-Side Comparison

The core trade-off is straightforward: a 15-year mortgage has higher monthly payments but costs far less over the life of the loan. A 30-year mortgage is more affordable monthly but charges you significantly more in total interest. Here is the math on a $350,000 loan.

Principal and interest only. Property taxes, insurance, and PMI are additional. Rates are illustrative examples; your actual rate will depend on credit score, down payment, and lender. Use our Mortgage Calculator to model your specific scenario.

Total Interest Cost by Loan Amount

The interest savings from a 15-year mortgage scale with the loan amount. Larger loans produce proportionally larger savings. Here is how five common loan amounts compare.

Calculated using the standard mortgage payment formula. Rates: 30-year at 6.50%, 15-year at 5.90%. Principal and interest only.

At every loan amount, the 15-year borrower pays roughly 60% less in total interest. On a $500,000 mortgage, that difference exceeds $383,000 -- enough to fund a substantial retirement account, college fund, or additional real estate purchase.

Monthly Payment Comparison: Can You Afford the 15-Year?

The interest savings are compelling, but the higher monthly payment is the main barrier for most borrowers. Here is a practical way to evaluate whether the 15-year payment fits your budget.

The 28% Rule of Thumb

Most lenders use the 28% rule: your total monthly housing cost (including taxes and insurance) should not exceed 28% of your gross monthly income. Here is what income you need for each term on a $350,000 loan.

Taxes and insurance estimated at $550/month for a home valued near $437,500 (assuming 20% down on $350,000 loan). Actual costs vary by location. Use our affordability guide for a personalized estimate.

The income gap is roughly $31,000 per year. If your household earns above $150,000 annually, the 15-year mortgage likely fits. If your income is between $120,000 and $150,000, you may want to evaluate other monthly obligations before committing to the higher payment.

Equity Buildup: How Fast You Own Your Home

One of the most significant advantages of a 15-year mortgage is how quickly you build equity. With a 30-year loan, most of your early payments go toward interest rather than reducing your loan balance. The shorter term reverses this pattern dramatically.

Equity from principal payments only; excludes home price appreciation. Based on $350,000 loan: 15-year at 5.90%, 30-year at 6.50%.

Why Equity Matters

Building equity faster has practical financial benefits beyond the satisfaction of owning more of your home:

• Eliminate PMI sooner -- if you put less than 20% down, faster equity buildup means you can drop private mortgage insurance earlier, saving $100-$300 per month
• Better refinancing terms -- higher equity gives you access to lower rates and better terms if you refinance in the future
• Home equity line of credit (HELOC) -- more equity means more borrowing power for renovations or emergencies
• Financial flexibility at retirement -- a paid-off home by your mid-40s or 50s significantly reduces your retirement income needs

The Opportunity Cost Argument: What If You Invest the Difference?

Some financial planners argue that taking the 30-year mortgage and investing the monthly payment difference could produce better long-term results. Here is how that math works -- and when it falls short.

The Investment Scenario

On a $350,000 loan, the 15-year payment is $722 more per month. If a 30-year borrower invests that $722 monthly at a 7% average annual return for 30 years, the investment grows to approximately $886,423.

Meanwhile, the 15-year borrower finishes their mortgage at year 15 and then invests their full former payment of $2,935 per month for the remaining 15 years. At 7%, that grows to approximately $935,590.

Assumes 7% average annual return, compounded monthly. Does not account for taxes on investment gains, inflation, or market volatility.

Why the Investment Argument Has Caveats

• Discipline required -- the 30-year strategy only works if you actually invest the difference every month for 30 years. Many people spend the savings instead
• Market risk -- a 7% return is a historical average for stocks, not a guarantee. Periods of poor returns could leave you worse off
• Tax drag -- investment gains are subject to capital gains taxes, while mortgage interest savings are guaranteed and tax-free
• Behavioral advantage -- a 15-year mortgage forces savings through required principal payments, which benefits those who struggle with investment discipline
• Peace of mind -- owning your home outright by age 45-50 provides financial security that is difficult to quantify

When a 15-Year Mortgage Makes Sense

A 15-year mortgage is generally the better choice when you meet most of the following criteria:

• The payment stays below 25-28% of gross income -- your total housing cost (PITI) fits comfortably within lending guidelines
• You have a fully funded emergency fund -- at least 3-6 months of expenses set aside, so the higher payment does not leave you vulnerable to unexpected costs
• You are already contributing to retirement -- maxing out or significantly contributing to your 401(k) or IRA before taking on the higher payment
• You have no high-interest debt -- credit cards and other high-rate debts should be paid off before committing to higher mortgage payments
• You plan to stay in the home long-term -- the interest savings are most significant over the full loan term. If you plan to move within 5-7 years, the savings advantage shrinks
• You want to be mortgage-free before retirement -- buying at age 35-40 with a 15-year term means your home is paid off by 50-55

When a 30-Year Mortgage Makes Sense

A 30-year mortgage is not simply the "worse" option -- it provides genuine financial advantages in many situations:

• The 15-year payment would strain your budget -- if the shorter term pushes housing costs above 30% of your gross income, the 30-year provides a necessary cushion
• You want to invest the difference -- if you have the discipline to invest the $722 monthly savings consistently, market returns may outpace the mortgage interest savings over 30 years
• You have other high-return uses for the money -- paying down 20%+ credit card debt, building a business, or maximizing 401(k) employer matches typically offer better returns than the 6.50% mortgage rate
• You value flexibility -- the 30-year loan allows you to make extra payments when you can afford it and skip them when finances are tight. You can always pay a 30-year like a 15-year, but you cannot reduce a 15-year payment if cash gets tight
• You are buying in a high-cost area -- in expensive markets, the 30-year term may be the only way to keep payments manageable
• You plan to move within 5-7 years -- if you will sell before the interest savings compound significantly, the monthly flexibility of the 30-year makes more sense

The 30-year mortgage with a voluntary extra payment strategy gives you the best of both worlds -- lower required payments with the option to accelerate payoff. The key is whether you will actually follow through on the extra payments. For guidance on making extra principal payments work, see our mortgage payment formula guide.

The Hybrid Strategy: 30-Year Loan, 15-Year Payoff

There is a middle path that many borrowers overlook: take a 30-year mortgage for its lower required payment, but make additional principal payments as if you had a 15-year loan. This provides flexibility while still reducing total interest costs.

How It Works

On a $350,000 loan at 6.50% (30-year rate), your required payment is $2,212. To match a 15-year payoff schedule, you would need to pay approximately $3,097 per month -- the equivalent of a 15-year payment at the same 6.50% rate.

The Trade-Off

• Advantage: If you lose your job or face a financial emergency, you can drop back to the $2,212 required payment -- an $885/month buffer
• Disadvantage: You pay the 30-year rate (6.50%) instead of the lower 15-year rate (5.90%), so total interest is higher than an actual 15-year mortgage. At the 30-year rate, paying off in 15 years costs $207,493 in interest versus $178,232 with an actual 15-year loan -- a difference of about $29,261

This strategy works best for borrowers who want the safety net of a lower required payment but have the income and discipline to consistently make extra payments.

Frequently Asked Questions

Making Your Decision: A Practical Framework

Use this framework to choose between a 15-year and 30-year mortgage:

1. Calculate both payments. Use our Mortgage Calculator with your actual loan amount and current rates for each term
2. Apply the 28% test. Does the 15-year total housing payment (PITI) stay below 28% of your gross monthly income? If yes, the 15-year is financially viable
3. Check your financial foundation. Do you have an emergency fund, retirement contributions on track, and no high-interest debt? If any of these are missing, the 30-year gives you breathing room to address them
4. Consider your timeline. Planning to stay 10+ years? The 15-year savings are substantial. Moving within 5-7 years? The monthly flexibility of the 30-year may matter more
5. Evaluate your discipline. Will you realistically invest the payment difference every month for 30 years? If not, the 15-year mortgage forces savings through required principal payments

There is no universally correct answer. The best mortgage term is the one that saves you the most money while maintaining financial stability and peace of mind. Run your own comparison with the calculator below.

Sources

• Freddie Mac -- Primary Mortgage Market Survey (PMMS) (opens in new tab)
• Consumer Financial Protection Bureau -- Owning a Home (opens in new tab)
• CFPB -- How Does My Mortgage Amortization Work? (opens in new tab)
• U.S. Department of Housing and Urban Development -- Buying a Home (opens in new tab)
• CFPB -- What Is Private Mortgage Insurance (PMI)? (opens in new tab)