See payoff dates with smarter monthly choices now. Add extra payments and track interest savings. Stay focused, reduce stress, and finish debt-free sooner together.
| Scenario | Balance | APR | Payment | Extra | Frequency | Estimated Payoff |
|---|---|---|---|---|---|---|
| Baseline | $12,000 | 18.5% | $350 | $0 | Monthly | ~43 periods |
| With Extra | $12,000 | 18.5% | $350 | $50 | Monthly | ~36 periods |
| Biweekly Push | $12,000 | 18.5% | $175 | $25 | Biweekly | Faster payoff |
Each payment period accrues interest using a periodic rate derived from APR:
If a lump-sum is scheduled, it reduces the balance on its date before normal interest and payment are applied. When the final payment would exceed the remaining balance, the tool adjusts it to pay exactly what’s needed.
A timeline turns a balance into dated milestones. Monthly means 12 payments per year, biweekly 26, and weekly 52. The calculator converts APR into a periodic rate (APR ÷ payments‑per‑year) and updates interest and principal each period. Example: $12,000 at 18.5% APR with a $350 monthly payment often runs about 43 periods, landing near a 3.5‑year payoff.
Interest equals balance × periodic rate, so early periods are the most expensive. In the $12,000 example, first‑month interest is roughly $185, leaving about $165 for principal. As the balance drops, interest shrinks and the same payment reduces principal faster. Cumulative interest helps you quantify the cost of delay and compare strategies objectively. If your payment barely exceeds interest, the balance falls slowly; raising payment by even 5% can shorten the finish line dramatically. Use the lump‑sum field to test one‑time payments and confirm how many periods they remove for your exact scenario.
Consistent extras steepen the payoff curve. Raising $350 to $400 can remove several months and save hundreds in interest. Rounding up makes this easier to sustain. Rounding a $392 total to $400 adds $8 per period; across 36 periods, that’s $288 of earlier principal, which typically cuts more than $288 of future interest.
Frequency changes when principal reductions occur. Biweekly schedules align with paychecks and can feel smoother; 26 payments can approximate “13 monthly” payments if you size the amount correctly. Weekly schedules reduce peaks in outstanding balance. The Plotly chart highlights how faster reductions shift interest lower throughout the timeline.
Use the payoff date as a target and the schedule as checkpoints. Export CSV to reconcile with statements and to track progress period by period. Re-run the model after refinancing, rate changes, or adding a lump sum from a bonus or refund. The best plan is repeatable: pay on time, increase gradually, and review cumulative interest every month.
1) Why does the payoff date change when I change frequency?
The interest rate is converted to a periodic rate based on payments per year. More frequent payments reduce principal earlier in the calendar, which can lower the interest charged over time and move the payoff date forward.
2) What does “payment too small to cover interest” mean?
If your payment for a period is less than or equal to that period’s interest, the balance will not decline. Increase the payment, add extra, reduce APR, or choose a different frequency.
3) How is the final payment calculated?
When the remaining balance is smaller than a normal principal amount, the calculator reduces the last payment to the exact amount needed to clear balance plus that period’s interest.
4) Will my lender match these numbers exactly?
Lenders may use daily compounding, different billing cycles, and fees. Use this as a planning and comparison model; your statement schedule can differ slightly, especially around partial periods and lump sums.
5) How should I set a biweekly payment amount?
A common approach is to divide your desired monthly payment by two and pay that every two weeks. For a closer “13th payment” effect, set biweekly to monthly × 12 ÷ 26.
6) What is the best way to use the Plotly chart?
Compare runs: baseline versus extra payments, rounding, or a lump sum. A steeper balance line and a lower ending cumulative interest line usually indicate a stronger payoff plan for the same time period.
Important Note: All the Calculators listed in this site are for educational purpose only and we do not guarentee the accuracy of results. Please do consult with other sources as well.