How Much Interest a $250,000 Mortgage Costs Over 30 Years — What It Really Means

When comparing a 30-year mortgage to a 15-year mortgage on a $250,000 loan, the differences in monthly payments and total interest paid become stark — especially when interest rates vary. The table below shows how the monthly payment and lifetime interest cost change across a range of APRs for both loan terms. This breakdown reveals not just the numbers, but the real trade-offs: shorter terms mean higher monthly payments but significantly less interest paid over time, while longer terms offer lower monthly obligations at the cost of far greater overall interest expenses.

How Monthly Payments Differ by Term and Rate

A 15-year mortgage will always have a higher monthly payment than a 30-year mortgage at the same interest rate, due to the shorter repayment period. For instance, at a 5% APR, the 15-year payment is nearly $1,600 more per month than the 30-year version. This difference grows at higher rates, where the impact of compounding interest becomes more pronounced. However, the trade-off is not just financial — it's also about flexibility. A 30-year loan allows for lower monthly stress, which can be crucial for someone with variable income or unexpected expenses. But over time, that flexibility comes at the price of hundreds of thousands of dollars in interest.

Why Total Lifetime Interest Varies So Much

The table shows that lifetime interest costs can be over $100,000 higher on a 30-year loan compared to a 15-year loan at the same rate. For example, at a 6% APR, the 30-year loan accumulates nearly $130,000 more in interest than the 15-year loan — even though the monthly payment is about $400 lower. This disparity is due to the longer duration of the 30-year loan, during which interest compounds over time. The longer the loan term, the more interest accumulates, even if the monthly payment is small. This makes the 15-year option not just more expensive per month, but more efficient in terms of total cost of ownership.

When Each Option Makes Sense

A 15-year mortgage is best for borrowers with stable incomes, strong credit, and a clear plan to pay off the loan early. It’s ideal for those who can afford higher monthly payments and are willing to commit to a shorter timeline — such as someone who plans to sell the home in 10–15 years or who has a significant financial cushion. Conversely, a 30-year mortgage suits those who prioritize affordability and financial flexibility. It allows for predictable, manageable payments, which is especially useful in volatile job markets or during life events like divorce or job transitions. However, the long-term cost of interest must be weighed against this flexibility.

How We Calculated This

The data in the table is derived from standard amortization formulas applied to a $250,000 loan. We used the fixed-rate mortgage formula: **Monthly Payment = P × [r(1+r)^n] / [(1+r)^n – 1]** Where P = loan amount ($250,000), r = monthly interest rate (APR ÷ 12), and n = total number of payments (30 or 15 years × 12). Total lifetime interest is then calculated by subtracting the principal from the total payments over the term. All figures are based on current standard APR ranges and do not include taxes, insurance, or fees. The table below shows the exact monthly payments and lifetime interest costs across the range of rates for both terms.

$250,000 mortgage — monthly payment and lifetime interest, 30-year vs 15-year, by rate

Rate	30-yr Payment	30-yr Interest	15-yr Payment	15-yr Interest
6.0%	$1,499	$289,595	$2,110	$129,736
6.5%	$1,580	$318,861	$2,178	$141,998
7.0%	$1,663	$348,772	$2,247	$154,473
7.5%	$1,748	$379,293	$2,318	$167,156