How this instrument works
A payoff figure is not the balance printed on last month's statement — it is that balance plus every day of interest that accrues between the statement date and the day the money actually arrives. Title companies, closing attorneys, and escrow officers request this number constantly, because a home sale or a refinance cannot close on a guess: the outgoing lender needs a dollar amount that is correct on one specific date, and that date is set by the closing schedule, not by the billing cycle. The gap between the two is per-diem interest, a small daily charge that adds up fast on a large balance.
The arithmetic stays simple on purpose. Between now and the payoff date no new payment posts and nothing compounds, so a servicer just multiplies the current balance by the annual rate divided by 365 to get one day's interest, then multiplies that by the day count and adds it back onto the balance. That is different from the monthly amortization math behind an ordinary mortgage payment, where interest recalculates against a shrinking balance every thirty days; a payoff quote only has to hold steady for the handful of days between now and closing, so the daily figure never needs to reamortize anything.
The total here is the pure interest math, not a lender's finished letter. Real payoff statements often add a reconveyance or recording fee, a wire-processing charge, or use a 360-day per-diem convention instead of 365, and every one of them is stamped 'good through' a single date because the number stops being accurate the moment that date passes. Treat the figure this instrument returns as the interest a closing agent should expect to see, not a replacement for requesting the servicer's own payoff letter before funds move.
- Enter the balance from your latest mortgage statement under Current principal balance, $ — the amount still owed today, not the original loan amount.
- Set Annual interest rate, % to the rate written on the note, or the rate currently in effect if the loan is adjustable.
- Count the calendar days between today and the date the payoff funds are expected to arrive, and enter that under Days until the payoff date.
- Read Per-diem (daily) interest to see exactly how much accrues for each day the closing is delayed.
- Read Total payoff amount due for the figure to request or wire on that specific date.
Worked example — a $250,000 balance, 15 days to closing
A homeowner with a $250,000 principal balance at a 6% annual rate asks their servicer for a payoff figure good through a closing 15 days away. Per-diem interest is the balance times the daily rate: $250,000 × (6 ÷ 100 ÷ 365) works out to $41.10 accruing for every day that passes. Multiply that by the 15 days and add it to the balance — $250,000 + ($41.10 × 15) — and the total lands at $250,616.44, the exact amount due on the day the closing agent expects the wire, not the $250,000 printed on last month's statement.
Push the closing back by a single day and the total climbs by another $41.10 — the reason a servicer stamps every payoff letter with a 'good through' date rather than leaving it open-ended. A closing agent who wires the stale $250,000 figure on day 15 comes up $616.44 short, and that shortfall turns into a lien the seller has to clear after the sale has already closed, usually with interest and a processing fee added on top.
Questions
Why isn't the payoff amount the same as my statement balance?
A statement balance is a snapshot from the last billing cycle, and interest keeps accruing every day after that snapshot is taken. A payoff figure adds per-diem interest — the balance times the daily rate — for every day between the statement and the date funds actually arrive, so a quote for a closing two weeks out always reads higher than the last posted balance.
Why does a payoff quote expire on a specific date?
Interest accrues daily, so the total grows by exactly one more day's per-diem for every day the payment is delayed. A servicer's 'good through' date marks the last day the quoted total is accurate; funds arriving after that date settle the account short by one day's interest for each day past the deadline, and the shortfall gets billed separately.
Will this match my lender's official payoff statement exactly?
Not necessarily. This instrument computes plain daily simple interest on the balance entered, while a real statement can add a reconveyance or recording fee, a wire-processing charge, or use a 360-day rather than 365-day convention for the daily figure. Treat the total here as the interest math to check a statement against, not a substitute for the servicer's own letter.
What if the exact closing date isn't confirmed yet?
Enter a best estimate under Days until the payoff date and rerun the figure once the date locks in — each extra or fewer day only shifts the total by one more day's per-diem interest, so an estimate a few days off still lands within a small dollar range of the real number.
Why is the interest calculated daily instead of compounding monthly?
No new payment posts between now and the payoff date, so there is no shrinking balance to reamortize against the way an ordinary mortgage payment schedule does. A servicer simply charges the daily rate on the same outstanding balance for each day that passes, which is why the math here stays a flat multiplication rather than a monthly recalculation.
References
- Consumer Financial Protection Bureau — Mortgage closing, what to expect
- Consumer Financial Protection Bureau — Mortgage servicing rules (Regulation X)
Read this first: This instrument shows arithmetic, not advice. Real offers add fees, taxes and terms that vary by lender and place — verify the figures against your actual paperwork before deciding anything.