To calculate how to calculate discount points, you need two formulas and three numbers. The upfront cost is your loan amount multiplied by 1% for each point you buy. The break-even point, which tells you whether buying points actually pays off, is that upfront cost divided by your monthly payment savings. Everything else is sourcing the right numbers and deciding how much weight to give them.
What One Point Costs and What It Buys
One discount point equals 1% of your loan principal. On a $300,000 mortgage, one point is $3,000. Two points are $6,000. The relationship stays linear no matter the loan size.1Consumer Financial Protection Bureau. How Should I Use Lender Credits and Points (Also Called Discount Points)?
You don’t have to buy whole points. Lenders routinely sell fractional points like 0.5 or 1.5, calculated the same way. Half a point on a $300,000 loan would cost $1,500.
In exchange, the lender permanently reduces your interest rate for the life of the loan. The reduction per point typically falls between 0.125% and 0.25%, and it varies by lender and loan type. That spread matters. A lender offering 0.25% per point gives you twice the rate reduction of one offering 0.125% for the same dollars, so comparing specific rate sheets is where the real analysis starts.
Where to Find Your Numbers
Every figure you need shows up on your Loan Estimate, which your lender must deliver within three business days of receiving your mortgage application.2Consumer Financial Protection Bureau. 12 CFR 1026.19 – Certain Mortgage and Variable-Rate Transactions The loan amount sits on page one under “Loan Terms.” Discount points appear on page two in Section A, listed under origination charges.1Consumer Financial Protection Bureau. How Should I Use Lender Credits and Points (Also Called Discount Points)?
You also need two numbers from the lender: the interest rate without points and the reduced rate with points. The gap between those rates drives every downstream calculation. If the quote is 7% as the base and 6.5% with two points, that 0.5% spread is what you’re paying for. Get both rates in writing before you run anything.
Calculating the Upfront Cost
Multiply the number of points by 0.01, then multiply by the loan amount:
Upfront cost = Loan amount × (Number of points × 0.01)
On a $300,000 mortgage with two points: $300,000 × 0.02 = $6,000. That $6,000 is due at closing alongside your down payment, title fees, and other settlement costs. It is not part of the down payment, and it does not reduce your loan balance. It’s a fee paid to the lender to buy a lower rate.1Consumer Financial Protection Bureau. How Should I Use Lender Credits and Points (Also Called Discount Points)?
The payment is generally non-refundable once the loan funds. Every dollar spent on points is a dollar unavailable for your down payment, moving costs, or a cash reserve after closing.
Calculating Your Monthly Savings
Monthly savings is the difference between your principal-and-interest payment at the original rate and the payment at the reduced rate. Any online mortgage calculator will produce both numbers. Focus only on principal and interest. Property taxes and homeowners insurance don’t change when you buy down the rate.
Using the $300,000 loan: at 7% over 30 years, principal and interest come to roughly $1,996 per month. At 6.5%, that drops to about $1,896. The difference is $100 per month, and that $100 is the return on your $6,000 at closing.
Run this with your lender’s actual quoted rates rather than round numbers. A small difference in the rate reduction can shift the break-even by a year or more.
Finding Your Break-Even Point
Break-even is how long you need to stay in the home before cumulative monthly savings equal what you paid upfront:
Break-even (months) = Upfront cost ÷ Monthly savings
With $6,000 in upfront costs and $100 in monthly savings, $6,000 ÷ $100 = 60 months, or five years. Every month past month 60 is net savings. Sell or refinance in month 48 and you lost money on the trade.
Most analysis stops there, and that’s where it needs to get more careful. The calculation assumes you keep the mortgage for its full remaining term. If rates fall and you refinance, your bought-down rate disappears with the old loan, and any unrecovered point costs are gone. That risk is why points are a harder sell when rates are historically high and expected to drop.
According to the National Association of Realtors, the median home seller in 2025 had owned their home for 11 years before selling.3National Association of Realtors. Top 10 Takeaways From NARs 2025 Profile of Home Buyers and Sellers A five-year break-even against an eleven-year hold leaves six years of net savings. But that median includes people who never planned to move quickly. If there’s any realistic chance you’ll relocate within a few years, points become a gamble.
Adjust the Math for Taxes
Points paid to buy your primary residence are generally deductible in the year you pay them if you meet IRS requirements. The points must relate to buying, building, or improving your main home. They must be computed as a percentage of the loan principal, clearly labeled as points on your settlement statement, and paid from your own funds rather than borrowed from the lender. The amount must also be in line with what’s customary in your area.4Internal Revenue Service. Topic No. 504, Home Mortgage Points
Refinance points work differently. You generally cannot deduct them all at once. Instead, you spread the deduction ratably over the life of the new loan. Pay $3,000 in points on a 15-year refinance and you deduct $200 per year ($3,000 ÷ 15) rather than $3,000 up front.5Internal Revenue Service. Publication 936, Home Mortgage Interest Deduction
This changes your break-even math. On a purchase, the first-year deduction cuts the effective cost of points and shortens your real break-even timeline. On a refinance, the tax benefit trickles in and barely moves the number.
If the Seller Is Paying the Points
In many purchases, the seller agrees to pay some or all of the buyer’s discount points as part of the deal. The IRS treats seller-paid points as if the buyer paid them directly, so you can still deduct them in the year of purchase if the usual requirements are met. The trade-off is that you must reduce the cost basis of your home by the amount of seller-paid points, which can affect your tax bill if you later sell at a gain.6Internal Revenue Service. Publication 530, Tax Information for Homeowners
Seller concessions, including points paid on your behalf, are capped on conventional loans backed by Fannie Mae. The limits depend on your loan-to-value ratio:
- LTV above 90%: capped at 3% of the sale price or appraised value, whichever is lower
- LTV between 75.01% and 90%: capped at 6%
- LTV at 75% or below: capped at 9%
- Investment properties: capped at 2% regardless of LTV
Concessions exceeding these limits get deducted from the sale price for underwriting purposes, which can throw off loan approval.7Fannie Mae. Interested Party Contributions (IPCs) When negotiating seller-paid points, make sure the total concession package stays within these thresholds.
A Ceiling on How Many Points You Can Buy
Federal rules limit total points and fees before a mortgage loses its Qualified Mortgage status. For loans of $137,958 or more in 2026, the cap is 3% of the loan amount, with wider caps for smaller loans.8Federal Register. Truth in Lending (Regulation Z) Annual Threshold Adjustments (Credit Cards, HOEPA, and Qualified Mortgages) The cap covers all points and fees combined, not just discount points. Origination fees and certain other charges count toward the total. Most lenders structure loans to stay inside QM limits, which puts a practical ceiling on how many discount points you can actually buy on a given loan.