What Does a Mortgage Cost at 4% Interest?
A 4% mortgage rate is well below historical averages and a significant advantage over current market rates. See the monthly payments, total costs, and how 4% stacks up against higher rates. For any loan amount at any rate, our monthly mortgage calculator gives you an instant breakdown.
Calculate Your Mortgage Payment at 4%
Understanding a 4% Mortgage Rate
4% was common in 2015–2019 and briefly available in early 2022 before the Federal Reserve began its rate-hiking cycle. At 4% on a $320,000 30-year loan, the monthly payment is approximately $1,528 in principal and interest, with total interest of $230,080 and a total cost of $550,080.
Compare that to 6.5% on the same loan:
- At 4%: $1,528/mo, $230,080 total interest
- At 6.5%: $2,023/mo — $495/mo more, $178,560 more in total interest
A 4% rate is highly favorable by historical standards and below the 50-year average of approximately 7.7%. Holders of 4% mortgages enjoy a material cost advantage over new buyers entering the market at current rates.
Monthly Payment at 4% by Loan Amount (30-Year Term)
See monthly payments and total interest at 4% across common loan sizes for a 30-year fixed mortgage.
| Loan Amount | Monthly Payment | Total Interest | Total Cost |
|---|
Even on a $500,000 loan, a 4% rate keeps the monthly principal and interest payment under $2,400 — a figure that would require only about $355,000 at 7%.
4% vs. 5% vs. 6% vs. 7% — Side-by-Side for $320K (30-Year)
Here is how your monthly payment and total interest change as rates rise from 4% on a $320,000 loan over 30 years.
| Rate | Monthly Payment | Total Interest | Extra vs. 4%/mo |
|---|---|---|---|
| 4% | $1,528 | $230,080 | — |
| 5% | $1,717 | $298,267 | +$189/mo |
| 6% | $1,919 | $370,774 | +$391/mo |
| 7% | $2,129 | $446,518 | +$601/mo |
The difference between 4% and 7% is $601/mo and over $216,000 in total interest — roughly two-thirds of the original loan amount paid purely in additional interest cost.
Frequently Asked Questions
Is 4% a good mortgage rate?
Yes — 4% is well below the 50-year historical average of ~7.7% and below the 2023–2024 market range of 6.5–8%. If available (e.g., via an assumable mortgage on a property), a 4% rate is exceptional. For new originations as of 2025, 4% is not achievable without significant discount points.
How much more do I pay at 4% vs 3%?
On a $300,000 loan over 30 years, 4% adds about $166/mo and $59,700 in total interest compared to 3%. Both rates are far better than current market rates.
Can you assume a 4% mortgage from a seller?
Yes — FHA and VA loans are assumable, meaning a buyer can take over a seller’s existing mortgage at the original rate (subject to lender approval and creditworthiness). Assuming a 4% mortgage in a 7% market can save hundreds of dollars per month. However, you typically need to compensate the seller for their equity, often requiring a second mortgage or large cash payment.
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Read the guide →What to Look For When Comparing Mortgage Rates
Even a 0.25% difference in your mortgage rate changes your total interest paid by tens of thousands of dollars over a 30-year term. When evaluating lenders, consider these factors alongside the headline rate:
- APR vs. interest rate — the APR includes origination fees and gives a more accurate total-cost comparison across lenders
- Points — paying discount points upfront lowers your rate but extends the break-even period; worthwhile only if you stay in the home long enough
- Fixed vs. adjustable — ARMs start lower but carry rate-reset risk after the initial period; fixed rates offer long-term payment certainty
- Lender type — banks, credit unions, and online lenders each offer different rate structures, underwriting timelines, and service models
- Rate lock period — confirm how long the quoted rate is guaranteed during the underwriting process before you are committed