Paste a book of past clients — balance, current rate, months left, and optionally a closing cost and your own profile note — type in the rate you are quoting today and the term you would write it on, and this screens every line the same way. For each client it shows the new payment against the current one, the monthly saving, the interest still owed on the current loan over its remaining term, the interest the new loan charges over that same window, and — separately, on its own line — the interest the new loan charges over its whole new term. That last figure is the one that gets left out: refinancing a twenty-year remainder into a fresh thirty-year loan very often raises lifetime interest while lowering the payment, and when it does, this tool says so in capitals. It also gives the break-even month on the closing cost, the rate change in basis points, and a flag against a threshold you set. It cannot watch the market — there is no network and no clock in this tool, it runs entirely on your machine — and it does not tell you to contact anyone. It ranks by the measure you choose and stops there.
Worked example
REFINANCE SCREENER — 5 clients screened against 6.00% over a 360-month term
Ranked by: Monthly saving
Flag threshold: 0 basis points — your number, not one this tool chose.
This tool cannot watch the market: it has no network and no clock. It screens the book against the one rate you typed above.
1. Everett LLC [FLAGGED]
Now $78,000.00 at 6.25% · 60 months left · payment $1,517.05
Quoted $78,000.00 at 6.00% · 360 month term · payment $467.65
Rate change 25 basis points (6.25% to 6.00%)
Monthly saving +$1,049.40
Interest still owed now, over 60 months $13,022.42
Interest on the new loan, over the same 60 months $22,641.41
Interest saved over the remaining term -$9,618.99
Interest on the NEW loan over its full 360 months $90,353.57
New loan, total repaid over its full term $168,353.57 = $78,000.00 balance + $90,353.57 interest
New loan, final payment $467.22 — settles the balance to exactly $0.00
Lifetime interest, new minus current +$77,331.15
** WARNING — this refinance RAISES total interest by $77,331.15 even though the payment falls. The term resets from 60 months to 360. **
Break-even not computed — no closing cost entered for this client
Loan age 60 months since closing
Your note no cost quoted yet
2. Chen, W. [FLAGGED]
Now $96,500.00 at 8.25% · 141 months left · payment $1,071.07
Quoted $96,500.00 at 6.00% · 360 month term · payment $578.57
Rate change 225 basis points (8.25% to 6.00%)
Monthly saving +$492.50
Interest still owed now, over 141 months $54,519.18
Interest on the new loan, over the same 141 months $61,974.38
Interest saved over the remaining term -$7,455.20
Interest on the NEW loan over its full 360 months $111,781.25
New loan, total repaid over its full term $208,281.25 = $96,500.00 balance + $111,781.25 interest
New loan, final payment $574.62 — settles the balance to exactly $0.00
Lifetime interest, new minus current +$57,262.07
** WARNING — this refinance RAISES total interest by $57,262.07 even though the payment falls. The term resets from 141 months to 360. **
Break-even on $2,400.00 of closing cost month 5
If this client sells, moves or refinances again before month 5, the refinance loses them money.
Loan age 219 months since closing
Your note self-employed, docs needed
3. Alvarez, R. [FLAGGED]
Now $312,450.00 at 7.125% · 322 months left · payment $2,179.08
Quoted $312,450.00 at 6.00% · 360 month term · payment $1,873.30
Rate change 112.5 basis points (7.125% to 6.00%)
Monthly saving +$305.78
Interest still owed now, over 322 months $389,205.07
Interest on the new loan, over the same 322 months $355,433.57
Interest saved over the remaining term +$33,771.50
Interest on the NEW loan over its full 360 months $361,933.40
New loan, total repaid over its full term $674,383.40 = $312,450.00 balance + $361,933.40 interest
New loan, final payment $1,868.70 — settles the balance to exactly $0.00
Lifetime interest, new minus current -$27,271.67
Break-even on $4,200.00 of closing cost month 14
If this client sells, moves or refinances again before month 14, the refinance loses them money.
Loan age 38 months since closing
Your note 60-day late in 2021
4. Brooks Family Trust [FLAGGED]
Now $184,900.00 at 6.50% · 268 months left · payment $1,309.38
Quoted $184,900.00 at 6.00% · 360 month term · payment $1,108.57
Rate change 50 basis points (6.50% to 6.00%)
Monthly saving +$200.81
Interest still owed now, over 268 months $166,010.10
Interest on the new loan, over the same 268 months $193,785.25
Interest saved over the remaining term -$27,775.15
Interest on the NEW loan over its full 360 months $214,184.24
New loan, total repaid over its full term $399,084.24 = $184,900.00 balance + $214,184.24 interest
New loan, final payment $1,107.61 — settles the balance to exactly $0.00
Lifetime interest, new minus current +$48,174.14
** WARNING — this refinance RAISES total interest by $48,174.14 even though the payment falls. The term resets from 268 months to 360. **
Break-even on $3,100.00 of closing cost month 16
If this client sells, moves or refinances again before month 16, the refinance loses them money.
Loan age 92 months since closing
Your note clean file
5. Dunn, P.
Now $442,000.00 at 5.875% · 349 months left · payment $2,645.00
Quoted $442,000.00 at 6.00% · 360 month term · payment $2,650.02
Rate change -12.5 basis points (5.875% to 6.00%)
Monthly INCREASE -$5.02
Interest still owed now, over 349 months $481,102.81
Interest on the new loan, over the same 349 months $511,144.86
Interest saved over the remaining term -$30,042.05
Interest on the NEW loan over its full 360 months $512,000.37
New loan, total repaid over its full term $954,000.37 = $442,000.00 balance + $512,000.37 interest
New loan, final payment $2,643.19 — settles the balance to exactly $0.00
Lifetime interest, new minus current +$30,897.56
** WARNING — this refinance RAISES total interest by $30,897.56 even though the payment does not fall. The term resets from 349 months to 360. **
Break-even never out of the payment — the payment does not fall, so the closing cost is never recovered monthly
Loan age 2019-04-11 — a closing date was given instead of a month count; this tool has no clock, so the loan's age is shown as the date you typed and nothing is computed from it
BOOK TOTALS — these are the sums of the lines printed above
Clients screened 5
Flagged at your 0 bps threshold 4
Payment falls for 4
Total interest RISES for 4 <- read those warnings before anything else
No break-even month could be stated for 2
Sum of the monthly savings above +$2,043.47
Sum of the interest saved over remaining terms -$41,119.89
THE SAME BOOK UNDER THE OTHER TWO MEASURES
Total interest saved over the remaining term: Alvarez, R. > Chen, W. > Everett LLC > Brooks Family Trust > Dunn, P.
Break-even speed: Chen, W. > Alvarez, R. > Brooks Family Trust > Dunn, P. > Everett LLC
A different measure gives a different order. That is not a defect — the fastest break-even and the largest lifetime saving are rarely the same client.
NOTES
· This projects the terms you entered and nothing else. It is not a quote, not an offer, not a lock, and not financial advice.
· Nothing here tells you to reach out to anyone, and no client is singled out for you. The order is the measure you picked; the decision, and whether there is a decision to make at all, is yours.
· The monthly saving is never shown on its own. Lowering a payment by resetting a 20-year remainder into a fresh 30-year term usually raises total interest, and the line above says so in capitals when it does.
· Break-even is the closing cost divided by the monthly saving, rounded UP to a whole month. A client who sells or refinances again before that month is worse off.
· Closing costs are priced as paid at closing, out of pocket. Rolling them into the balance instead makes the new loan larger than the figure used here.
· This cannot see the client's credit, income, escrow, mortgage insurance, prepayment penalty, cash-out need, or whether they still own the property. The profile note is carried through as text; it changes no number.
· No rate, closing cost or 'refinance when rates drop' rule is built in. The values this page starts with are an invented example, not market data, and every one of them should be replaced with yours.
· Monthly interest is charged on the balance and rounded half away from zero at the cent; the level payment is the smallest cent amount that retires the balance, so the final payment is the small one and the schedule lands on exactly $0.00.
Frequently asked
What format do the lines take?
name | balance | current rate % | months left | months since closing | closing cost | note. Separate the fields with a pipe, semicolon or tab; only the first four are required. A comma works too, but only on a line that uses no other separator — otherwise "$312,450.00" would split in two. Dollar and percent signs are ignored. Lines beginning with # are treated as comments.
Does this watch rates and tell me who to call?
No, and it is worth being straight about why. This tool has no network connection and no clock, so there is nothing for it to watch and no month for it to wake up in. You supply today's rate. It also produces no call list: it ranks the book by the measure you pick and leaves the decision, including whether there is one, to you. The arithmetic across a whole book, done identically on every line, is the part that was ever hard.
Why show total interest as well as the monthly saving?
Because the monthly saving on its own is how people are sold a worse loan. A lower rate on a longer term almost always lowers the payment; it frequently raises the total interest paid over the life of the loan, sometimes by more than the payment saving ever returns. Both figures are printed for every client, side by side, and a refinance that raises lifetime interest is flagged with a warning naming the amount.
How is the break-even month calculated?
Closing cost divided by the monthly saving, rounded up to a whole month, because a partial month has not yet recovered the cost. If the payment does not fall, there is no monthly saving to divide by and the tool says so rather than printing a number. If no closing cost was entered for a client, it says that instead of assuming one — closing costs vary by lender, state and loan size, so a built-in figure would be confidently wrong.
What rate should trigger a flag?
Whatever you decide. The flag threshold is a field you fill in, in basis points, and it starts at zero, which flags every client whose rate is above the rate you entered. There is no built-in rule of thumb here — the familiar ones ('refinance at one percent', 'at two percent') are marketing, they depend entirely on loan size and closing cost, and they go stale.
Why do the three rankings disagree?
Because they measure different things. The largest monthly saving usually belongs to the biggest balance; the largest lifetime interest saving often belongs to a shorter remaining term; the fastest break-even belongs to whoever has the smallest closing cost relative to their saving. The output prints the order under all three so the disagreement is visible rather than hidden behind whichever one you happened to pick.
What can it not see?
Credit, income, appraised value, escrow, mortgage insurance, a prepayment penalty on the existing note, cash-out needs, and whether the client even still owns the property. It projects the numbers on the line and nothing more. It is not a quote, not an offer and not financial advice.
I pasted a closing date and it did not compute the loan's age.
Correct — deliberately. There is no clock in this tool, so it cannot know what today is and cannot subtract. A date is carried through as text next to the client so you can read it; a month count in that field is used as-is.