How it works
Calculate the normal fixed payment, then apply one extra principal payment after the regular payment in the chosen month. Keep the normal payment afterward and stop when paid off.
Input definitions
- Original remaining principal
- Enter the value in the labeled unit.
- Nominal annual rate (%)
- Enter the value in the labeled unit.
- Remaining scheduled months
- Enter the value in the labeled unit.
- Month of lump sum (after regular payment)
- Enter the value in the labeled unit.
- One-time extra principal payment
- Enter the value in the labeled unit.
A worked example
- Original remaining principal
- 1200
- Nominal annual rate (%)
- 0
- Remaining scheduled months
- 12
- Month of lump sum (after regular payment)
- 3
- One-time extra principal payment
- 300
Assumptions & limits
Single-currency illustration using your entered amounts and rates, not a recommendation, approval or forecast. No automatic tax rules or market data.
Sources & review
Maintained by AnsRio. Methods and examples use automated checks; this does not imply independent professional certification.
Method updated 2026-10-17. Content checked against the stated method and examples. Our verification approach.
Common questions
Does a one-time extra payment reduce my next regular payment?
This tool keeps the regular payment unchanged and shortens payoff time. A formal loan recast instead changes future scheduled payments; lender rules and charges are separate.
How does One-time loan overpayment schedule work?
Calculate the normal fixed payment, then apply one extra principal payment after the regular payment in the chosen month. Keep the normal payment afterward and stop when paid off.
What are the limits of One-time loan overpayment schedule?
Single-currency illustration using your entered amounts and rates, not a recommendation, approval or forecast. No automatic tax rules or market data.
How do I keep the full worksheet?
Run the tool and choose Download file. The on-page table is a preview and may show only the first 20 rows; the downloaded file contains the full result. CSV downloads escape spreadsheet formula prefixes. Inputs and files are processed on your device.