A lender’s radio ad promises refinancing will knock “hundreds” off your monthly payment. Sometimes that’s true. Sometimes it’s a $9,000 gamble that takes nearly three years just to break even. The honest answer sits somewhere between those two, and you can work it out with three numbers you already have: your current rate, your balance, and how many years are left.
Let’s go through what a realistic payment drop looks like, where it comes from, and the situations where refinancing quietly does nothing for you at all.
The short answer: about 8% to 10% per percentage point
If you refinance purely to grab a lower rate and keep the same 30-year term, your principal and interest payment falls by roughly 8% to 10% for every full point you shave off the rate. On a typical mortgage, here’s what that looks like on a $350,000 balance:
- 7.5% rate: $2,447 per month
- 6.5% rate (one point lower): $2,212, saving $235 a month
- 6.25% rate: $2,155, saving $292 a month
- 6.0% rate (a 1.5 point drop): $2,098, saving $349 a month
So a moderately good rate cut on a mid-sized loan is worth somewhere between $200 and $350 a month in real cash. That’s $2,800 to $4,200 a year, which is meaningful money. It’s just not usually the $600 headline figure on the flyer, and it isn’t automatic.
Where that payment number actually comes from
It is not a flat percentage and it is not linear. Your payment is driven by an amortisation formula that spreads your balance plus interest across a fixed number of months. The rate sits in that formula twice, which is why small rate changes feel amplified near the top end and barely register at the bottom.
Drop from 7.5% to 6.5% and you free up nearly 10% of your payment. Drop from 4.25% to 3.75% and you’ll notice maybe 6%. The same half-point means different things depending on where you started, which is a big part of why the real savings from refinancing vary so wildly from one household to the next.
One more thing the calculator won’t tell you: your new loan starts the clock over at month one. If you had 24 years left and you refinance into a fresh 30-year term, the payment drops further, but about 20% of your new monthly payment goes to interest in year one versus the higher share you were paying on a shorter remaining term.
Three levers that decide how far your payment falls
Lever 1: the interest rate
This is the lever everyone focuses on, and rightly so. A full point on a $350,000 balance is worth around $235 a month. Locking in a fixed rate also removes future uncertainty, though whether that certainty is worth the closing costs depends on how long you plan to stay. There’s a decent breakdown of that trade-off in whether locking in a fixed rate actually saves money.
If you’re currently on an adjustable-rate mortgage, the math changes shape entirely. You may be facing a reset that will raise your payment regardless of what you do, in which case refinancing isn’t only about lowering the payment today, it’s about stopping a scheduled increase. That scenario is covered properly in when refinancing an adjustable-rate mortgage pays off.
Lever 2: the clock
Stretching the term is the most powerful way to shrink a payment, and the most expensive. Take a $280,000 balance at 6.5% with 22 years remaining. The payment is about $1,996. Refinance into a 30-year term at the same rate and it drops to roughly $1,770, a saving of $226 a month for doing nothing but adding eight years.
Those eight years cost about $110,000 in additional interest. The payment falls, the wealth doesn’t. If you want the full picture of how this lever works, read up on how stretching your mortgage lowers payments and what it costs before you sign anything.
Lever 3: your balance, your PMI, and what you extract
A smaller loan balance means a smaller payment at any rate. Paying the balance down before you refinance multiplies the benefit, because every dollar you cut is removed from thirty years of interest.
Mortgage insurance is the quiet lever. On a $350,000 loan, PMI at 0.6% adds about $175 a month. If your home has appreciated enough that you’re now under 80% loan-to-value, a refinance can drop that charge entirely, and $175 is bigger than the savings from most rate cuts. Go the other way, though, and take cash out, and your payment rises instead of falling on two counts: a bigger balance at a slightly higher rate.
What refinancing costs, and the month you break even
Closing costs on a rate-and-term refinance typically run 2% to 5% of the loan amount. On $350,000 that’s $7,000 to $17,500, with a straightforward file usually landing around $8,000 to $10,000 once lender fees, title, appraisal, and recording charges are added up.
Divide that by your monthly saving to get the break-even point. In the example above, $8,000 divided by $292 is about 27 months. If you sell or refinance again before month 27, you lose money on the deal. That single calculation matters more than the rate itself, and it’s the one lenders tend to leave off the comparison sheet. There’s a useful tool for stress-testing it in the number the bank’s refinance calculator leaves out.
Three reasons the payment drop comes in smaller than promised
- Escrow ignores your interest rate. Property taxes and homeowners insurance usually rise every year. Your principal and interest might fall $290 while your escrow portion climbs $90, leaving a net drop of $200.
- “No closing cost” means a higher rate. The lender isn’t waiving anything. It’s charging a higher rate to cover the fees, which can cost you 0.25% to 0.5% in rate, or roughly $60 to $120 a month on a $350,000 loan.
- You may restart PMI. Refinancing resets the mortgage insurance clock on some loan types. If you were two years from automatic PMI removal, a refinance can push it back out.
When refinancing won’t lower your payment at all
Small balances are the classic trap. Fixed costs like appraisal, title, and underwriting don’t shrink with the loan. On a $140,000 balance, a 1% rate cut saves about $94 a month, and $7,000 in closing costs takes over six years to recover. That’s usually not worth it.
Same problem if you only have 10 or 12 years left. Stretching back to 30 years would lower the payment, but you can achieve a version of that without a full refinance. A mortgage recast, where you pay a lump sum toward principal and the lender re-amortises the remaining balance over the original schedule, costs a few hundred dollars and requires no credit check or income documentation. It’s worth knowing how a recast shrinks your payment without refinancing before you pay thousands for the same outcome.
And if your current rate starts with a 3 or a 4, there is essentially nothing to gain. Refinancing out of a 3.5% loan into a 6.5% loan to pull out equity raises your payment by hundreds a month, permanently.
Working out your own number in ten minutes
Grab your mortgage statement and do this in order:
- Note your current principal and interest payment, not the total including escrow.
- Run your balance, remaining term, and a realistic new rate through an amortisation calculator. Use the rate your lender actually quoted you in writing, not the advertised one.
- Ask for a Loan Estimate and add up box A, B, C, and E. That total is what you’re paying to get the new payment.
- Divide the total cost by the monthly saving. If the answer is more than about 36 months and you’re not certain you’ll stay, walk away.
A payment drop of $290 a month feels great until you notice it cost $9,200 to get and you’re selling in two years. Run the break-even month, check whether a recast or a lump-sum principal payment gets you closer to the same result for less, and compare the new payment against your total cost of borrowing over the life of the loan rather than just the next twelve months. The rate is the headline. The break-even date is the story.