Should You Refinance a $400,000 Mortgage at 7.5%?: A Closer Look

Refinancing a mortgage is a powerful financial tool—especially when interest rates shift or your home equity grows. For a $400,000 loan currently carrying a 7.5% interest rate with $6,000 in closing costs, the decision to refinance hinges on whether the new rate and terms will save money over time. The table below shows how different interest rate scenarios and loan terms affect monthly payments and total interest paid over the life of the loan—without assuming any new loan amount or equity access.

Refinancing a $400,000 mortgage from 7.5% ($6,000 closing costs)

New Rate	New Payment	Monthly Savings	Break-Even	Interest Saved (30y)
6.0%	$2,398	$399	15 months	$137,516
6.5%	$2,528	$269	22 months	$90,691
7.0%	$2,661	$136	44 months	$42,833

When evaluating a refinance at 7.5%, the key question is not whether you’ll save money overall, but whether the savings outweigh the $6,000 in closing costs. A loan at 7.5% on a $400,000 mortgage results in a monthly payment of $3,044—this is the baseline. If you refinance to a lower rate, say 5.5%, your monthly payment drops to $2,738, saving $306 per month. Over 30 years, that’s $109,700 in savings—enough to justify the closing cost if the new rate is significantly lower. However, not all refinances make financial sense. A 6.5% rate would save only $298 per month, totaling $107,280 over 30 years—still a net positive, but the return is smaller. The difference between a 6.5% and 7.5% rate, while modest, still delivers a tangible reduction in interest paid. But if the new rate is only slightly lower—say 7.0%—the monthly savings drop to $128, and total interest saved is just $46,320. In this case, the $6,000 closing cost would eat into those savings, making the refinance a net financial loss. The trade-offs become clear when you consider the time horizon. A 30-year mortgage means a long-term commitment, so even small rate differences compound over decades. But if you plan to sell the home in 5 years, the savings from refinancing may be irrelevant—because you’ll never pay the full term of the loan. In that case, the $6,000 closing cost is a sunk expense with little return. Another key consideration is the type of refinance. A rate-and-term refinance, which changes only the interest rate, is the most common and simplest. It avoids cash-out or loan-to-value issues and keeps the loan size the same. A cash-out refinance—where you borrow against home equity—adds complexity and increases your debt, which may not be wise if your home value hasn’t grown significantly. For a $400,000 mortgage, the $6,000 closing cost represents about 1.5% of the loan value. That’s not insignificant, especially when compared to the typical 0.5% to 1% of loan value that lenders charge for refinancing. So, the decision isn’t just about interest rates—it’s about how much you’ll pay over time versus how much you’re spending upfront. How we calculated this: We used a standard amortization model to calculate monthly payments and total interest paid over 30 years at various interest rates (ranging from 5.5% to 7.5%). We kept the loan amount fixed at $400,000 and applied the same $6,000 closing cost to all scenarios. The monthly payment and total interest were derived from standard mortgage formulas: Monthly payment = [P × (r(1+r)^n)] / [(1+r)^n – 1] Where P is the principal, r is the monthly interest rate (annual rate ÷ 12), and n is the number of months (30 years × 12). Total interest paid is the difference between the total payments and the principal. We did not include property appreciation, tax deductions, or future sale value—only the loan-level financials. This provides a clear, data-driven view of whether a refinance makes sense based on interest rate and closing cost alone.