GUIDE
Keeping a low rate when you move
Moving usually means a new loan. On the same balance and term, the rate you leave behind is worth the payments you would not be making.
The same balance, a new rate
Take $400,000 with 25 years left at 2.75%. The payment is $1,845 a month. At the 7.40% average from October 8, 2026, the same loan is $2,930 a month. That is $1,085 more each month.
Over the remaining term, the extra payments add up to about $325,426 before discounting. Discounted at 7.40%, that gap is worth $148,089 today. That is the number the calculator prints.
The 30-year Treasury yield saved for October 8, 2026 is 5.60% (FRED series DGS30). On this balance it sits 2.85 points above 2.75%, about $11,400 a year.
What the figure is, and is not
The math is the present value of an annuity: the monthly gap, discounted at the comparison rate, for the years left. It is the same calculation as the home page.
It does not know whether you can assume the old loan, what the next house costs, or what a lender would approve. Closing costs, taxes, insurance, and points are outside it. The 2.75% rate is an example a homeowner might still hold. The 7.40% average is a published print, not a guess at a missing week.
Open this example in the calculator
Questions
- What is a low rate worth if I give it up to move?
- On a $400,000 balance with 25 years left, 2.75% against the 7.40% average from October 8, 2026 is worth $148,089. That is the present value of the extra monthly payment, discounted at 7.40%. The calculator uses the same math.
- Does this assume I borrow the same amount?
- Yes. The comparison keeps the $400,000 balance and the 25-year term, and changes only the rate, from 2.75% to the 7.40% average. A different purchase price is not in the figure.
- When would the monthly gap close?
- The monthly payment on this same balance matches when the average 30-year rate is 2.75%. That is the break-even rate in the calculator. It leaves out closing costs, taxes, insurance, and a different house.
- Where does the comparison rate come from?
- The 7.40% figure is the Freddie Mac Primary Mortgage Market Survey average saved for October 8, 2026 (FRED series MORTGAGE30US). The archive page for that date is https://www.lockedat.com/rates/2026-10-08.
An estimate, not financial advice or a loan quote.