Mortgage Discount Points Calculator
Estimate the cost of buying mortgage discount points, the monthly savings from a lower rate, and how many months it takes to break even. Enter loan amount, term, both rates, and points.
Buying Mortgage Points Cost and Savings Calculator
Mortgage Discount Points Formula
Where:
- \(P\) — loan principal (amount borrowed)
- \(r\) — monthly interest rate (annual rate divided by 12)
- \(n\) — total number of monthly payments (loan term in months)
- \(d\) — discount points purchased, as a percentage of the loan amount
- \(M\) — monthly payment (calculated for both the rate with points and the rate without points)
- \(S\) — monthly saving from the lower rate
- \(T\) — break-even time in months
The first formula is the standard amortizing-loan payment formula, applied once at the rate with points and once at the rate without points. The break-even time tells you how long you must keep the loan before the monthly savings have repaid the upfront cost of the points.
Mortgage Discount Points – Calculation Example
Example: you borrow \(\$300{,}000\) for 30 years. The lender offers a rate of 4.5% with no points, or 4.0% if you buy 1 discount point. You expect to stay in the home for 7 years.
\[ \text{Fee for Points} = 300{,}000 \times \frac{1}{100} = \$3{,}000 \]
\[ M_{\text{with}} = \frac{300{,}000 \times 0.04/12}{1 - (1 + 0.04/12)^{-360}} \approx \$1{,}432.25 \]
\[ M_{\text{without}} = \frac{300{,}000 \times 0.045/12}{1 - (1 + 0.045/12)^{-360}} \approx \$1{,}520.06 \]
\[ S = 1{,}520.06 - 1{,}432.25 = \$87.81 \quad\Rightarrow\quad T = \frac{3{,}000}{87.81} \approx 34.2 \text{ months} \]
Result: the point costs \($3,000\) upfront, saves \($87.81\) per month, and breaks even after about 34.2 months (roughly 2 years and 10 months). Over the planned 7 years (84 months), the total savings are about \($7,376\) — a net gain of roughly \($4,376\) after the cost of the point.
How to Use the Calculator
- Enter the Loan Amount — the principal you are borrowing, not the home price.
- Enter the Loan Term (Years), typically 15, 20, or 30 years.
- Enter the Interest Rate With Points — the lower rate the lender offers if you buy points.
- Enter the Discount Points (%) — each point equals 1% of the loan amount. Enter 1 for one point, 1.5 for one and a half.
- Enter the Years in Home — how long you realistically expect to keep this mortgage before selling or refinancing.
- Enter the Interest Rate Without Points — the rate you would pay if you bought no points.
- Read the results: Monthly Payment With Points, Fee Paid for Points, Monthly Payment Without Points, Monthly Saving, and Break-even Time in months.
What Are Mortgage Discount Points?
Discount points are an upfront fee paid to a lender in exchange for a lower interest rate — a practice often called "buying down the rate." One point costs 1% of the loan amount, so on a \($300,000\) mortgage, one point costs \($3,000\). Each point typically lowers the rate by somewhere between 0.125% and 0.5%, depending on the lender and market conditions, so always ask for your lender's exact rate sheet.
Buying points is essentially a trade-off: you pay more at closing to pay less each month. The calculator quantifies both sides of that trade. It shows the upfront fee, the two monthly payments, the monthly saving, and — most importantly — the break-even time, which is the number of months of savings needed to recover the upfront cost.
Interpreting the result is straightforward: if the break-even time is shorter than the number of months you expect to keep the loan (your Years in Home times 12), buying points comes out ahead. If you might sell, refinance, or pay off the loan before the break-even point, the points are a losing bet because the upfront fee is sunk at closing.
Because points reduce the interest rate on the entire loan, the longer you keep the mortgage, the more valuable they become. For a fuller picture of the payments themselves, run the same numbers through our Mortgage Calculator or the Mortgage Payment Calculator. Points also affect the loan's effective cost over time, which is captured in the Mortgage APR Calculator.
Limitations and Practical Tips
- The break-even ignores opportunity cost. The \($3,000\) spent on points could otherwise be invested or used for a larger down payment. If you want to weigh the alternative, compare against the Return on Investment Calculator.
- Monthly savings are not perfectly constant. The calculator uses the first month's payment difference for the whole term. In reality the difference shifts slightly over time because the two loans amortize at different speeds; the effect on break-even is small.
- Points do not always reduce the rate by the same amount. The rate reduction per point varies by lender, loan type, and market. Get both rates (with and without points) in writing from your lender before running the numbers.
- Discount points are not the same as the origination fee. Some lenders charge an origination fee quoted in "points" for processing the loan; only true discount points buy the rate down.
- Points may be tax-deductible in some jurisdictions as prepaid mortgage interest. Consult a tax professional, since rules depend on how the loan is used and where you live.
- Cash at closing matters. Even when points are mathematically worthwhile, you need the liquidity to pay them. A point paid from savings you might need later can be riskier than a slightly higher rate.
- Refinancing resets the clock. If you are likely to refinance soon — for example, because rates are expected to fall — the points on the current loan may never break even.
Frequently Asked Questions
How many discount points should I buy?
There is no universal number — it depends on how long you keep the loan. A common rule of thumb is that each point lowers the rate by roughly 0.25%, but the actual reduction varies by lender and market. Compare break-even times for different point amounts: if buying 2 points breaks even in 5 years but you plan to sell in 4, buy fewer points or none. Always get your lender's rate sheet showing the rate at 0, 1, 2, and 3 points before deciding.
How much does one discount point lower my interest rate?
Typically between 0.125% and 0.5% per point, most often around 0.25%. The reduction is not fixed — it varies by lender, loan type, and daily market conditions, and it can change from day to day. On some days lenders offer better 'buydown' pricing than others, so the same point can be worth more or less depending on when you lock your rate. Ask your lender for both quotes in writing.
Are discount points paid upfront or rolled into the loan?
They are normally paid in cash at closing, but many lenders allow you to finance them by adding the cost to the loan balance. Rolling points into the loan means you pay interest on that amount for the life of the mortgage, which stretches out the break-even time. If you finance the points, recalculate the break-even using the higher loan balance — the calculator assumes the fee is paid in cash at closing.
Is buying points worth it if I plan to refinance later?
Usually not. Refinancing replaces your current mortgage, so any points you paid are effectively lost once the old loan is paid off. If rates are expected to fall and you are likely to refinance within a few years, the points may never break even. Only buy points when you are confident you will keep this specific mortgage well past the break-even month — for example, when rates are already relatively high and unlikely to drop soon.
Do discount points lower my monthly payment or my loan balance?
They lower the interest rate, which reduces your monthly payment — the loan balance stays exactly the same. For example, dropping from 4.5% to 4.0% on a $300,000 30-year loan cuts the payment by roughly $88 per month. Points are sometimes confused with a larger down payment, which does reduce the principal. A bigger down payment also avoids interest but costs more per dollar of monthly savings in many cases.
Are mortgage discount points tax-deductible?
In the United States, discount points on a loan for your primary residence are generally deductible as prepaid mortgage interest in the year paid, subject to IRS rules and itemization. Points paid on a refinance or for an investment property are usually deducted differently — often spread over the life of the loan. Rules vary by country and change over time, so keep your closing disclosure and consult a tax professional before counting on the deduction.
What is the difference between discount points and an origination fee?
Discount points are prepaid interest that buys down your rate. An origination fee is a charge for processing and underwriting the loan — some lenders quote it in 'points' too, but it does not lower your rate. A lender advertising 'no points' may still charge an origination fee. When comparing loan offers, look at the Loan Estimate form: discount points appear in Section A and must be clearly labeled, so you know exactly what you are paying for.
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