15-year vs 30-year mortgage: which saves more money?

The 30-year mortgage is America's default home loan — but it's not always the right choice. Here's a clear-eyed look at the real numbers behind both options.

The basic math on a $300,000 loan

The 15-year mortgage saves nearly a quarter million dollars in interest on a $300,000 loan. That's not a rounding error — it's a life-changing amount of money.

Why the 15-year rate is lower

Lenders charge less for 15-year mortgages because there's less risk over a shorter period. Rates are typically 0.5–0.75% lower than 30-year rates. That rate difference plus the shorter term combine for a dramatic interest savings.

The case for the 30-year

The 30-year isn't just for people who "can't afford" the 15-year. There are legitimate reasons to choose it:

• Cash flow flexibility: The lower required payment gives you breathing room during tough months
• Investment opportunity: If your investments return more than your mortgage rate, the math can favor investing the difference rather than paying down the mortgage faster
• Other high-interest debt: If you have credit cards at 22%, paying them off is a better return than accelerating a 7% mortgage
• Emergency fund first: Building savings before overextending on mortgage payments is often the wiser move

The hybrid approach

Take a 30-year mortgage for the lower required payment, but pay extra toward principal each month. You get the flexibility of a lower minimum payment with the interest savings of a faster payoff. Even paying an extra $300/month on a $300,000 30-year mortgage at 7% cuts 8 years off the loan and saves over $120,000 in interest.

Which is right for you?

Choose the 15-year if: you have a stable high income, no high-interest debt, a full emergency fund, and maxed retirement contributions. Choose the 30-year if: your income is variable, you have other financial priorities, or the higher payment would strain your monthly budget.