15 vs 30-Year Mortgage: A Complete Side-by-Side Comparison
Choosing between a 15-year and 30-year mortgage is one of the most consequential decisions in the entire homebuying process. The difference in total interest paid can exceed $300,000 on a typical loan — but the 15-year option comes with a significantly higher monthly payment that can strain budgets and limit financial flexibility. Here's everything you need to make the right call for your situation. Use our Loan Comparison tool to model both options with your exact numbers.
The Numbers: A Direct Comparison
Assumes $350,000 loan. Current avg rates May 2026. Use our Mortgage Calculator for your exact figures.
Why 15-Year Rates Are Lower
The 15-year fixed rate is typically 0.5–0.75% below the 30-year fixed rate. This is because shorter-term loans represent less risk to the lender — there's a shorter window during which the borrower could default or rates could change. That lower rate compounds the savings: you're paying less interest, for fewer years, at a lower rate.
The Case for a 30-Year Mortgage
The 30-year mortgage remains the most popular mortgage in America for good reasons:
- Cash flow flexibility: The lower required payment gives you breathing room for emergencies, job changes, or other financial priorities without risking your home
- Investment opportunity: The extra $694/month you're not paying toward a 15-year loan could be invested. At 7% historical market returns over 30 years, that $694/month grows to approximately $875,000 — more than the interest difference
- Qualification: A lower required payment means you may qualify for a larger loan amount, enabling you to buy in a better location or larger home
- Optionality: A 30-year mortgage with extra payments is functionally equivalent to a 15-year mortgage — with the option to pay less during tough times
The Case for a 15-Year Mortgage
- Guaranteed return: The interest saved is a guaranteed, risk-free return equal to your mortgage rate (~6.14%). Most investors would be delighted with that risk-free.
- Forced discipline: The higher payment creates forced savings via equity, unlike investing which requires discipline to maintain
- True financial freedom: Owning your home outright at the end of 15 years — potentially before retirement — provides security no investment account can replicate
- Lower total cost: You simply pay far less for the home over its lifetime
- Build equity faster: Faster equity growth provides a financial cushion and more options (refinance, HELOC, downsizing)
The "30-Year With Extra Payments" Strategy
Many financial advisors recommend a hybrid approach: take the 30-year mortgage but make extra payments when possible, targeting the payoff speed of a 15-year loan. This gives you:
- The lower required payment of a 30-year (insurance against tough times)
- The payoff speed of a 15-year (when you make the extra payments)
- Flexibility to dial back payments during financial stress
On a $350,000 loan at 6.82% (30-yr), paying an extra $694/month pays the loan off in approximately 16.5 years and saves about $270,000 in interest — nearly as good as the 15-year at a fraction of the commitment. Use our Extra Payment Calculator to model this for your loan.
The Right Choice Depends on Your Priorities
Breaking Down the Investment Argument
The math on investing the payment difference is compelling on paper — but requires discipline and consistent execution over 30 years. In practice, many people spend the payment difference rather than investing it. The 15-year mortgage creates forced savings that happen automatically.
Also worth noting: the investment return comparison changes significantly based on your mortgage rate. At current rates (6.82%), the "invest the difference" argument requires the market to return more than 6.82% after tax — which is plausible historically but not guaranteed. At lower rates (3–4%), the investment argument is much stronger.
How to Run the Numbers for Your Situation
- Use our Mortgage Calculator to calculate both monthly payments at your loan amount and current rates
- Use our Loan Comparison tool to see 15yr vs 30yr side by side with total interest
- Honestly assess whether the 15-year payment fits your budget with comfort to spare
- Consider the "30-year with extra payments" approach using our Extra Payment Calculator