How to Calculate Mortgage Discount Points ROI (And When They're Not Worth It)

What Discount Points Actually Cost You

A discount point is prepaid interest. You pay it at closing to buy down your mortgage rate. One point equals 1% of the loan principal. On a $400,000 loan, one point costs $4,000.

The rate reduction per point varies by lender, loan type, and market conditions. The typical range is 0.20 to 0.25 percentage points per point purchased. Some lenders quote 0.125 points per point bought when rates are volatile. Others offer 0.375 in a competitive market. Never assume. Ask for the exact reduction in writing before you calculate anything.

The upfront payment is real cash out of pocket. It does not reduce your loan balance. It does not earn interest. It sits at closing as a sunk cost until your monthly savings accumulate enough to cancel it out.

The Break-Even Formula

The calculation has three inputs and one output.

Inputs:

• Upfront cost of the points
• Monthly payment without points
• Monthly payment with points

Output:

• Break-even month

The formula:

“

Break-Even Month = Upfront Point Cost / Monthly Savings

Monthly savings equals the difference between your payment without points and your payment with points. That number stays fixed for the life of a fixed-rate loan.

If you sell or refinance before the break-even month, you lose money on the points. If you stay past it, you profit.

Worked Example 1: The Standard 30-Year Purchase

Loan amount: $500,000. Rate without points: 7.10%. Rate with two points: 6.60%.

Two points on a $500,000 loan cost $10,000 upfront.

Monthly payment at 7.10%: $3,361.
Monthly payment at 6.60%: $3,197.
Monthly savings: $164.

Break-even: $10,000 / $164 = 61 months, or just over five years.

If you hold the mortgage for 30 years, the total interest saved at the lower rate reaches approximately $59,040. Subtract the $10,000 upfront cost. Net benefit: $49,040.

If you sell in year four, month 48, you recover $7,872 in savings against a $10,000 cost. Net loss: $2,128.

The decision is entirely a function of how long you hold the loan. Nothing else changes the math.

Worked Example 2: The Refinance Scenario

Loan balance: $320,000. You are 5 years into a 30-year mortgage at 7.50%. You want to refinance into a new 30-year at 6.75%, and the lender offers 6.50% with 1.5 points.

1.5 points on $320,000: $4,800 upfront.

Monthly payment at 6.75% (new 30-year): $2,076.
Monthly payment at 6.50%: $2,023.
Monthly savings from buying down: $53.

Break-even: $4,800 / $53 = 90.6 months, or 7.55 years.

That is a long horizon to recoup $4,800. If there is any reasonable probability you refinance again within seven years, or if rates fall another 75 basis points in the next 18 months, the points purchase destroys value.

In this scenario, taking the 6.75% rate without points is almost certainly the better choice. The savings per month are too small relative to the upfront cost.

When Points Generate Real ROI

Points make financial sense under specific, measurable conditions.

You have a long, stable horizon. Primary residence buyers who plan to hold for 10 or more years benefit substantially from even a modest rate reduction. On a $600,000 loan, reducing the rate from 7.25% to 6.75% via two points saves $197 per month. Break-even arrives at month 61. By year 20, accumulated savings total $47,280 net of the $12,000 upfront cost.

You are buying at your forever home. The 30-year hold eliminates all break-even risk. Every month past break-even is pure gain.

You have surplus cash at closing. Points purchased with savings you would otherwise park in a 4.5% money market account carry an opportunity cost. Account for it. The actual break-even extends slightly when you factor in the foregone return on that capital.

Tax deductibility applies. Mortgage points paid on a home purchase are generally deductible in the year paid, subject to IRS rules. Points paid on a refinance are deducted over the loan's life. Consult a tax advisor. The deduction improves your effective ROI.

When Points Destroy Value

Short holding periods. The average American refinances or sells within 7 to 8 years. For buyers in transitional situations, shorter expected hold times make points a poor allocation of capital.

Rising probability of refinance. If you buy when rates are elevated and expect them to fall, paying points is counterproductive. You pay upfront to reduce a rate you plan to abandon.

High-opportunity-cost cash. Cash used to pay points cannot compound elsewhere. A $10,000 point payment invested at 7% annual return grows to $19,672 over 10 years. Compare that against your cumulative payment savings before committing.

ARM loans. Paying points on a 5/1 or 7/1 ARM is rarely defensible. The rate floats after the fixed period ends. You may hit break-even just as the rate adjusts upward anyway.

The Opportunity Cost Adjustment

The simple break-even formula ignores what you could earn on the upfront point payment. A more precise ROI calculation discounts both the savings stream and the foregone investment return.

Adjusted break-even formula:

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Adjusted Break-Even = Upfront Cost / (Monthly Savings - Monthly Opportunity Cost)

Monthly opportunity cost equals: (Upfront Cost × Annual Return Rate) / 12.

Using Worked Example 1 with a 5% alternative investment return:
Monthly opportunity cost: ($10,000 × 0.05) / 12 = $41.67.
Adjusted monthly net savings: $164 - $41.67 = $122.33.
Adjusted break-even: $10,000 / $122.33 = 81.7 months, or 6.8 years.

The standard calculation said 61 months. The adjusted calculation says 82 months. That difference matters when your expected hold period sits between those two numbers.

Most lenders and real estate agents quote the simple break-even. They do not account for opportunity cost. That is the number that misleads buyers into purchasing points they should not.

H3: What Lenders Won't Tell You

Lenders profit whether you buy points or not. Their incentive is to close the loan, not to optimize your total cost of ownership.

A lender who shows you a side-by-side comparison of three rate options, with and without points, is doing their job. A lender who quotes you only the lowest rate and buries the point cost in the loan estimate is not.

Read the Loan Estimate carefully. Section A, "Origination Charges," is where points appear. They are labeled "Discount Points" or "Points." Some lenders use the phrase "buying down the rate" without specifying a point count. Ask for the exact upfront cost per 0.125% of rate reduction. Build the table yourself.

Run Your Numbers Before You Commit

The variables that determine whether discount points pay off are specific to your loan, your rate environment, and your plans. No general rule applies cleanly.

The CalcMoney mortgage calculator handles the full break-even and ROI analysis. Input your loan amount, the rate with and without points, the point cost, and your expected hold period. The output shows break-even month, cumulative savings at any horizon, and adjusted ROI accounting for opportunity cost.

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Points on a $600,000 loan at current rates can mean $12,000 or more at closing. That decision deserves more than a lender's summary. Run the full analysis with the CalcMoney mortgage calculator →