30-Year vs 15-Year Mortgage: The Math That Matters
7 min read
A 15-year mortgage costs more per month but saves a fortune in interest. Here's when each makes sense — with real numbers.
## The headline tradeoff 15-year loans typically have ~0.5–0.75% lower rates and pay off in half the time. Monthly payments are ~30–50% higher.
## Real example on $320,000 - **30-yr at 6.5%**: ~$2,022/mo, ~$408k interest. - **15-yr at 5.75%**: ~$2,657/mo, ~$158k interest. - **You save**: ~$250,000 in interest.
Verify with our [Amortization Calculator](/amortization).
## When 30-year wins - Cash flow matters and you'll invest the difference. - Job income is volatile. - You may move within 7 years.
## When 15-year wins - You're past peak earning years. - You hate debt and want freedom by retirement. - Forced savings appeals to you.
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Written and reviewed by
Keiron Brown, Psy.D.
Founder & Lead Educator, CalculatingWealth
Keiron Brown, Psy.D., is a clinical psychologist and the founder of Relationale LLC, which publishes CalculatingWealth. His doctorate is in psychology, not finance: he is not a registered investment adviser, accountant, or attorney, and nothing here is financial, investment, tax, or legal advice. His work here focuses on financial education, critical thinking, and decision-making — helping people understand the math behind money so they can plan with clarity and confidence. He writes about wealth building, retirement planning, investing literacy, budgeting, and the behavioral patterns that shape long-term financial outcomes.
Editorial standards: All educational content on CalculatingWealth is reviewed for accuracy, sourced from primary references where applicable (IRS, SSA, Federal Reserve, BLS), and updated when rules or rates change. Content is for educational and informational purposes only and does not constitute financial, investment, tax, or legal advice.
Not advice: Keiron Brown is not a registered investment adviser, broker-dealer, certified public accountant, enrolled agent, attorney, or licensed insurance producer. His work is educational in nature. See our full disclaimer.