15 vs 30 Year Mortgage: Which Should You Choose?

Choosing between a 15-year and a 30-year mortgage is one of the biggest financial decisions you make as a homebuyer. The 15-year loan slashes lifetime interest and builds equity twice as fast, but the higher payment locks you in. The 30-year loan stays cheap and flexible, but you pay dramatically more interest over time. Here is the honest, math-first comparison.

The Math on a $400,000 Loan

Assume today's typical rates: 5.85% for a 15-year and 6.75% for a 30-year. Run the numbers and the difference is striking:

The 15-year saves over $330,000 in interest — about 80% of the original loan amount. But it requires an extra $752 per month in cash flow.

Why 15-Year Rates Are Lower

Lenders charge less for shorter loans because they are less risky. There is less time for default, inflation, or market shifts to hurt the lender. The typical spread is 0.5–0.75%. Combined with paying interest for half as long, the 15-year is the clear winner on math — but math is not the whole story.

Pros and Cons of a 15-Year Mortgage

Pros

• Significantly lower interest rate
• Pay off the home in half the time
• Save hundreds of thousands in lifetime interest
• Build equity dramatically faster
• Mortgage-free heading into retirement

Cons

• 30–50% higher monthly payment
• Less budget flexibility for life changes
• Less cash flow for retirement and investing
• Harder to qualify for the same home price
• Locked into the higher payment — no easy way to lower it

Pros and Cons of a 30-Year Mortgage

Pros

• Lowest required monthly payment
• Easier to qualify for a more expensive home
• Frees up cash for retirement, investing, kids, emergencies
• Optional extra payments can mimic a 15-year payoff

Cons

• Roughly 0.5–0.75% higher interest rate
• Total interest can exceed the original loan amount
• Slow equity building in early years
• Easy to never make extra payments and stay in debt for 30 years

The Hybrid Strategy Most Experts Recommend

The smartest play for many buyers is to take a 30-year loan but voluntarily make extra principal payments each month — often enough to mimic a 20-year payoff. This captures most of the interest savings while keeping the lower required payment as a safety net during job changes, medical expenses, or recessions.

On the $400,000 example above, paying an extra $500/month on a 30-year loan saves roughly $185,000 in interest and pays it off in about 21 years instead of 30 — without locking you into the higher required payment.

When 15 Years Wins

• Stable, predictable income
• 6+ months of emergency fund already saved
• Retirement contributions already at the match (or maxed)
• The 15-year payment is no more than 25% of take-home pay

When 30 Years Wins

• Early in your career or variable income
• Want maximum cash flow for investing
• Buying in a high-cost market where 15-year is unaffordable
• Plan to use the cash flow for kids, business, or retirement contributions

Frequently Asked Questions