Required-payment descent, accelerated staircase, and dated lump-sum landingLive current inputs
Finance & Money
Personal Loan Payoff Calculator
Build an accelerated personal-loan payoff schedule with recurring extra principal, a dated lump sum, interest savings, and milestone checkpoints.
Payoff time with plan—
Required-only payoff time—
Months saved—
Interest with plan—
Required-only interest—
Interest saved—
Estimated final payment—
Payoff feasibility—
Payoff milestone staircase
Required-payment descent, accelerated staircase, and dated lump-sum landing
Two balance paths share the same opening debt. The lump-sum month is marked as a distinct landing so its timing effect is visible.
Live decision table
Accelerated payoff ledger
Inspect balance, interest, scheduled payment, extra principal, and milestone status at decisive months.
| Month | Opening balance | Interest and fees | Required payment | Extra principal | Closing balance |
|---|
Cash-flow schedule
Annual and monthly cash-flow schedule
How to plan
Use the balance and payment from the latest statement
- Enter the current payoff balance.
- Include recurring account fees.
- Place a lump sum in its realistic month.
- Confirm extra payments are principal-directed.
Payoff method
Timing changes interest saved
An earlier lump sum reduces the balance that generates every later interest charge. The same amount paid near the end saves less.
The model caps the final payment so it does not overstate borrower cash.
Calculation method
Simulate monthly interest and payment allocation until the balance reaches zero
Each month adds interest and servicing fees, applies the required payment, then applies recurring and dated extra principal. A second simulation removes all extra payments for a like-for-like baseline.
Detailed calculation process and general formulas
I_m = B_(m-1)·APR/12 + FX_m = E + L·1(m=k)B_m = max[B_(m-1)+I_m-P-X_m,0]Months saved = M_base-M_planInterest saved = I_base-I_plan Symbols, meanings, and units
- B_m
- closing balance in month mcurrency
- I_m
- monthly interest and fee chargecurrency
- P
- required paymentcurrency/month
- E
- recurring extra principalcurrency/month
- L
- one-time lump sumcurrency
- k
- lump-sum monthmonth number
- M
- months to payoffmonths
The worked example below substitutes the current inputs in formula order and reconciles the headline result with the visual and live table.
Execution
Protect the plan from avoidable friction
- Check prepayment restrictions.
- Keep the required payment on autopay.
- Retain proof of principal-only instructions.
- Request a final payoff quote before the last payment.
Acceleration anatomy
Where the payoff improvement comes from
Recurring extra principal and a dated lump sum create separate drops in the balance staircase.
Time saved
—Difference between required-only and accelerated payoff.
Interest avoided
—Financing cost removed by earlier principal reduction.
Final payment
—Capped amount needed in the payoff month.
Decision takeaway: Prioritize extra principal only after protecting essential liquidity and higher-cost obligations.
Practical applications
Decisions this calculator is designed to support
Annual bonus lump sum
A borrower plans a bonus payment eight months from now while adding a smaller amount monthly.
What the result clarifies: The staircase separates the recurring and one-time effects.
Required payment barely above interest
A high-rate loan has a low contractual payment.
What the result clarifies: The feasibility result warns when the entered payment cannot amortize the balance.
Worked example
Current-input substitution and reconciliation
Important note
This projection does not replace a lender payoff quote. Daily interest, posting dates, fees, prepayment penalties, and principal-allocation rules can change the exact final amount.
Personal Loan Payoff Calculator FAQ
Why can payoff be impossible?
If payment does not exceed monthly interest and fees, the balance cannot decline without extra principal.
Is the lump sum applied before interest?
It is applied after that month's interest and required payment.
Why is the final payment smaller?
The model caps it at the remaining balance plus that month's charge.