PropertyIf you bought a home before 2022 and have been watching mortgage rates inch from 3% to over 6%, you already know the number in your gut. But here is what most homeowners have not actually sat down and calculated: the precise monthly dollar penalty for giving up your low-rate mortgage and buying something new.
On a $300,000 loan balance, switching from 3.8% to the current 30-year fixed rate of 6.36% (Freddie Mac Primary Mortgage Market Survey, May 14 2026) adds $471 to your monthly principal and interest payment. Every single month. That is $5,650 per year. Over a decade, it is $56,495, before you have spent a cent on a bigger home, better schools, or a shorter commute.
This is the real reason inventory is frozen. It is not that homeowners do not want to move. It is that the financial cost of moving has rarely been this high in modern history.
Get this in your inbox every Friday.
One email. The number that matters and what it means for you.
The full payment table by loan size
The numbers below are principal and interest only, they exclude property taxes, insurance, and HOA fees, which you would pay at any rate. All calculations use a 30-year fixed term.
| Loan balance | Payment at 3.8% | Payment at 6.36% | Monthly extra | Extra over 10 years |
|---|---|---|---|---|
| $150,000 | $699 | $934 | $235 | $28,200 |
| $200,000 | $932 | $1,246 | $314 | $37,700 |
| $250,000 | $1,165 | $1,557 | $392 | $47,000 |
| $300,000 | $1,398 | $1,869 | $471 | $56,500 |
| $350,000 | $1,631 | $2,180 | $549 | $65,900 |
| $400,000 | $1,864 | $2,492 | $628 | $75,300 |
| $500,000 | $2,330 | $3,114 | $785 | $94,200 |
The table above compares remaining balance at the old rate to the same balance borrowed fresh at 6.36%. In practice, most people who move up will borrow more, which makes the real-world gap even wider. If you sell a $350,000 home and buy a $500,000 home, you are not just absorbing a higher rate, you are absorbing it on a larger principal.
Why the gap between old and new rates matters so much right now
The gap between the rate people are holding and the rate available today is what economists call the "lock-in effect." And the numbers behind it are staggering. More than three-quarters of US mortgage holders carry a rate below 6%, according to 2026 industry data. Roughly 40% hold a rate below 4%, including the flood of buyers and refinancers who locked in during 2020 and 2021, when rates briefly touched 2.65% on the 30-year fixed.
The lock-in effect does not just hurt buyers. It squeezes inventory for everyone. When existing owners will not sell, the pool of resale homes stays small. That kept prices elevated in 2023 and 2024 even as rates doubled, and it continues to suppress listings today. The 4.4 months of national supply that NAR reported for April 2026 (the most inventory since 2019) is largely driven by new construction, not by existing homeowners listing their properties.
On a $300,000 loan at 3.8%, you pay $203,234 in total interest over 30 years. At 6.36%, that same balance costs $372,720 in interest, a difference of $169,486. That is not a rounding error. That is a second car, a child's college education, or a decade of retirement contributions.
The real question: what does your equity do while you wait?
Here is where it gets more complicated. Framing the decision purely as "my payment goes up $471 a month" misses half the picture. What happens to your equity if you stay put?
National home prices rose just 0.9% year-over-year in April 2026 (NAR). That is the slowest appreciation in four years. In markets like Austin, prices have fallen 2–3%. In the Northeast, they are still climbing. But the era of 15–20% annual gains that made staying put feel like an obvious win is over, at least nationally.
If your current home appreciates at 1% per year and your target home appreciates at 2% per year (say, a larger home in a better school district), you are losing ground every year you delay. The opportunity cost of waiting compounds just as surely as the interest on a new loan.
This does not mean moving is the right call for everyone. It means the decision is more nuanced than "rates are high so I'll stay." The correct framing is: what is the cost of staying versus the cost of going, over your specific time horizon?
Five scenarios where paying the premium makes sense
1. A life event that overrides the math. Divorce, job relocation, family expansion, these are not financial calculations. They are life. A $471/month payment increase is genuinely painful, but so is commuting two hours a day or living in a house that no longer fits your family. The number is real. It is not always the deciding number.
2. You have substantial equity and can keep the loan balance small. If you have paid down or appreciated your way to a low loan-to-value ratio, the absolute dollar gap shrinks fast. A borrower who needs $150,000 rather than $300,000 is looking at $235/month extra, not $471. Significant equity changes the calculation materially.
3. You are buying in a market where prices are still falling. If you are moving from a stable market to one where prices are correcting (and buying before the trough) you may acquire the new home at a discount that more than compensates for years of higher payments. Austin, parts of Florida, and several Mountain West cities still show price softness in 2026.
4. Your income has risen significantly since you bought. A $471/month premium was a much larger percentage of a $60,000 salary than it is of a $95,000 one. If your household income has grown substantially since you last bought, the affordability calculus is different. The mortgage is the same absolute cost. Your capacity to service it is not.
5. You can plan for a refinance within 3–5 years. Fannie Mae projects the 30-year rate will average 6.1–6.2% in the second half of 2026, with further declines possible in 2027. If you buy now on the assumption you will refinance to a meaningfully lower rate within five years (and if that happens) the effective lifetime cost of the new mortgage drops sharply. The risk is that rates stall higher than forecast. That is a real risk. But it has a name: rate risk. You can price it.
The scenario most people are not running
Here is a worked example for a homeowner in a situation similar to many who bought in 2019–2021.
Suppose you bought a Chicago-area home in 2020 for $380,000 with 10% down, at a rate of 3.8%. Your original loan was $342,000. After six years of payments and modest appreciation, your home is now worth roughly $420,000 and your remaining balance is approximately $302,000. You have around $118,000 in equity.
You want to upsize to a $520,000 home. You sell, pocket $118,000 (minus transaction costs of roughly $30,000, leaving $88,000 net), and put that down on the new property. Your new loan: $432,000 at 6.36%.
Your old payment (on the remaining $302k balance at 3.8%): $1,407/month P&I.
Your new payment ($432k at 6.36%): $2,694/month P&I.
The difference: $1,287 per month.
That is not a typo. When you factor in that you are borrowing a larger amount at a higher rate, the combined effect is substantial. You are not just absorbing the rate difference. You are absorbing it on a 43% larger loan.
That $1,287/month buys you a home $140,000 more expensive. Whether that is worth it depends on what that $140,000 gets you: square footage, location, schools, lifestyle. Numbers do not make that call. You do. But you should make it with these numbers in front of you, not without them.
What the data says most owners are actually doing
Most are staying put. The NAR reports that the average tenure in a home has risen from roughly six years before the pandemic to more than eight years today. The rate lock-in effect is real and measurable: by one estimate cited in a Federal Reserve study, the lock-in effect suppressed existing-home sales by roughly 1.3 million annually at peak rate levels in 2023.
The situation is slowly unwinding. Some homeowners who locked in 3% mortgages in 2020 are now facing enough life pressure (growing families, career moves, ageing parents) that they are selling regardless of the rate penalty. The 24 consecutive months of year-over-year inventory growth through late 2025 reflects that gradual unfreezing. But "slowly unwinding" is not the same as "solved." If you are waiting for inventory to flood back to pre-2020 levels, you are probably waiting for a while.
What this means for you
If you hold a sub-4% mortgage and are weighing a move, here is the straight-line advice: do not make the decision without running your specific numbers. The difference between a $150,000 loan and a $432,000 loan is a $235/month penalty versus a four-figure monthly increase. Those are different decisions.
Three things are worth calculating before you commit either way. First, what is the actual monthly cost difference for your specific loan sizes, not a generic $300k example? Second, what is your breakeven if rates drop and you refinance within three to five years? Third, what is the opportunity cost if you stay put and the market you want to buy into appreciates faster than the one you are in?
The rate gap is the biggest financial constraint facing American homeowners right now. Acknowledging the size of it is not a reason to freeze. It is a reason to do the maths properly, and then make a decision you can live with.
Use the PropertyPundit mortgage calculator to run your specific numbers: loan size, both rates, and projected timeline.