Loan Payoff Calculator
See how much time and interest an extra monthly payment could save.
Verify this calculatorMaintained
See what the result uses—and what it cannot know.
Sumvoro calculates deterministically from the visible inputs. It does not invent lender terms, local rules, market values, medical facts, or professional judgments.
- 1 · InputsCheck every entered value against the latest statement, quote, measurement, or official source.
- 2 · Formula
Each month: interest = balance × annual rate ÷ 12. Principal repaid = payment + extra − interest. Repeat until the balance reaches zero. - 3 · SensitivityUse Insights to run a lower and higher case. If the conclusion changes easily, collect better information or leave more margin.
- 4 · ScopeThis tool is maintained and covered by automated calculation tests. Provider timing, rounding, and omitted facts can still change a real-world result.
- Formula release
- 2026.10-r4
- Release date
- October 10, 2026
- Review status
- Maintained
- Source review
- September 12, 2026
Optional readingLearn how this calculator works
How the loan payoff calculator works
Calculate how extra monthly payments affect your payoff time, total interest, and remaining loan cost.
Each month: interest = balance × annual rate ÷ 12. Principal repaid = payment + extra − interest. Repeat until the balance reaches zero.
Read our calculation methodology and limitations.
Example
Compare a $20,000 balance at 8% with $450 regular monthly payments against paying an extra $100 each month.
What affects the result
- Extra principal payments reduce future interest on the remaining balance.
- A payment that does not cover monthly interest cannot pay down the loan.
- The final payment is limited to the balance and interest still due.
Helpful guides
Frequently asked questions
Does this include a prepayment penalty?
No. Check your agreement and lender instructions before making extra payments. The model assumes the extra amount goes to principal.
Why might my lender give a different payoff date?
Daily interest, payment dates, fees, and rounding can differ. This calculator uses monthly interest and a fixed payment schedule.