Mortgage Discount Points Break-Even Calculator: When Buying Down Your Rate Makes Sense

When a lender offers you the option to "buy down" your rate with discount points, they're making a business offer. For the right buyer, it's a good deal. For the wrong buyer, it's an expensive prepayment on savings you'll never see.

The break-even calculation tells you which one you're looking at.

What Mortgage Discount Points Are

One discount point costs exactly 1.0% of your total loan amount, paid upfront at closing. In exchange, your lender permanently lowers your interest rate — typically by 0.25% per point, though this ratio varies by lender and market conditions.

On a $350,000 loan:

• 1 point = $3,500 upfront
• Rate reduction: approximately 0.25%
• Example: rate drops from 7.00% to 6.75%

Two points = $7,000 upfront, rate drops to 6.50% (if lender offers standard ratio).

The upfront cost is fixed, certain, and paid at closing. The savings are monthly, ongoing, and contingent on how long you keep the loan.

The Break-Even Formula

Break-Even Months = Total Cost of Points ÷ Monthly Payment Savings

Worked example:

• Loan: $350,000
• Rate without points: 7.0% → Monthly P&I: $2,329
• Rate with 2 points ($7,000): 6.5% → Monthly P&I: $2,212
• Monthly savings: $117
• Break-even: $7,000 ÷ $117 = 59.8 months (approximately 5 years)

If you sell, refinance, or pay off the loan before month 60, you paid $7,000 and only recovered a portion of it in monthly savings. After month 60, every monthly payment is $117 cheaper — money you keep.

The Full 30-Year Picture

After the break-even point, points generate pure savings. Over 30 years on the same example:

• Total savings from rate reduction: $117 × 360 = $42,120
• Cost of points: $7,000
• Net lifetime savings: $35,120

But this assumes you keep the loan for 30 years. How many people actually do?

The median time a US homeowner stays in their home is 8–10 years. The median time a mortgage is held before refinancing historically ran 5–7 years before the current high-rate environment (refinancing surged when rates fell, effectively resetting most loans). In today's market, with rates elevated and fewer refinance incentives, loan retention is longer — which actually strengthens the case for buying points when break-even is under 5 years.

The key question is: what's your realistic hold period?

The Cost of Buying Down Your Rate: How the Numbers Scale

Using $350,000 loan at 7.0% base rate, lender pricing at standard 0.25% reduction per point:

The break-even tends to be consistent because the cost and savings scale proportionally. What changes is the total amount at stake. Three points on a $500,000 loan is $15,000 upfront.

Note: Lender pricing is not always linear. Sometimes 1 point buys 0.375%; sometimes 0.20%. Always get the specific rate sheet from your lender and calculate for your actual offer, not a theoretical ratio.

When Points Are Worth Buying

Clear "buy" signals:

1. You're certain to stay 7+ years. If you're buying your "forever home" in a stable city, and break-even is 5 years, points are almost certainly worth it.

2. Break-even is under 36 months. Short break-even periods justify points even for buyers with uncertain plans.

3. You have cash and low-rate alternatives are scarce. Buying points is essentially a guaranteed return equal to your mortgage rate (because the savings are guaranteed, unlike stock market returns). If your savings account earns 4.5% and your mortgage rate is 7%, the 7% guaranteed equivalent return from points is compelling.

4. Rates are near a high, and refinancing before break-even would be irrational. If rates spike to 7.5% and are expected to fall, you'd expect to refinance — but if rates are near peak and you're locking a 30-year, the case for points strengthens.

Clear "don't buy" signals:

1. You might sell or move within 3–4 years. Job uncertainty, growing family, relationship changes — any of these could force a sale before break-even.

2. You're planning to refinance as soon as rates drop. If you pay $7,000 in points today and refinance in 18 months when rates fall 1%, you've paid $7,000 for 18 × $117 = $2,106 in savings. A $4,894 loss.

3. The cash is better deployed elsewhere. If you have credit card debt at 20% or haven't built an emergency fund, the $7,000 for points produces worse financial outcomes than eliminating that high-rate debt.

4. You're already at or near your cash limit. Stretching to cover points and closing costs while draining reserves is a liquidity risk. A one-time large expense in month 6 could put you in a real bind.

Fractional Points and Seller-Paid Buydowns

Points don't need to be round numbers. Many lenders allow fractional points — you can buy 0.5 points, 1.75 points, whatever ratio your budget and math support.

Seller concessions can also fund buydown. In a buyer's market or a slow-selling property, you might negotiate for the seller to pay $7,000 in closing costs on your behalf, and direct that $7,000 to buying points. You effectively get the rate reduction at no out-of-pocket cost — which dramatically changes the break-even math (essentially zero break-even period).

In 2023–2026, temporary buydown structures ("2-1 buydowns" and "3-2-1 buydowns") became common as sellers tried to make higher-rate environments more palatable to buyers. These are different from permanent discount points — they reduce your rate for years 1–2 only, then revert to the original rate. The math is different and should be evaluated separately.

The Opportunity Cost Calculation

Points compare to an alternative: don't buy points, invest the cash.

$7,000 invested in an index fund at 8% average annual return over 10 years = approximately $15,100.

$7,000 in points at a 5-year break-even, held for 10 years = approximately $117 × 60 months of net positive savings = $7,020 net benefit (cost recovered plus 5 years of savings).

In this simplified comparison, the investment wins. But this ignores:

• The mortgage interest savings are guaranteed; equity returns are not
• The effective after-tax return of points is the mortgage rate (often 7%+), which is higher than the 4–5% after-tax expected return on stocks for many tax situations
• Points reduce a required payment, which has consumption value independent of the pure investment comparison

The honest answer: points are not obviously better or worse than investing the difference. They're different in nature — one is a guaranteed fixed-rate equivalent return, the other is variable and growth-oriented. Your mortgage rate, investment alternatives, and time horizon all matter.

The Mortgage Math & Affordability Calculator Toolkit includes a points break-even worksheet that calculates your specific break-even timeline, compares total interest savings across different holding periods, and models the opportunity cost of the upfront cash. You input your actual lender's rate-point structure, not a theoretical ratio.

For UK, Australian, and Canadian Buyers

In the UK, "arrangement fees" or "product fees" serve a similar function to US discount points — you pay more upfront for a lower interest rate. The same break-even logic applies, but the calculation period is shorter because UK fixed terms end at 2–5 years, not 30. A £999 fee on a 2-year fix at a lower rate has a very different break-even than a $7,000 fee on a 30-year US mortgage.

In Australia and Canada, the concept of discount points isn't as standardized. Lenders may offer different rate options at different fee structures, and the analysis framework is identical — calculate the upfront cost, calculate the monthly savings, divide to find break-even — but verify the specific product mechanics with your lender.

The One-Sentence Decision Rule

If your break-even period is shorter than your expected time in the home before selling or refinancing, buy the points. If it isn't, don't. Everything else is noise.