Repayment Calculator
Repayment Calculator
The Repayment Calculator generates complete loan amortization schedules and shows how extra payments can accelerate your debt payoff and save money on interest. Whether you have a mortgage, auto loan, student loan, or personal loan, understanding your repayment schedule is the first step toward making smart financial decisions about your debt.
Most loans use simple amortization where each payment is divided between interest and principal. In the early years, the majority of each payment goes toward interest. Extra payments can dramatically reduce both payoff time and total interest. Even modest additional payments made consistently can save thousands of dollars.
There are several strategies for extra payments: adding a fixed amount to each payment, making one extra full payment per year, or applying lump sums when you receive bonuses or tax refunds. All are effective, but consistency and starting early produce the best results.
Enter the loan principal, annual interest rate, and loan term. You can optionally enter a recurring extra payment or a one-time extra principal payment. Press Calculate to compare the standard repayment schedule against the accelerated schedule.
The results show total payments, total interest, and payoff date under both scenarios. For example, a $25,000 auto loan at 6 percent for 5 years has a $483 payment and $3,999 total interest. Adding $50 per month saves $468 in interest and pays off the loan 8 months early.
Standard periodic payment:
For each period, interest portion and principal portion:
Extra payments on a $300,000 mortgage at 6.5 percent over 30 years:
| Extra Monthly | Payoff Time | Total Interest | Interest Saved |
|---|---|---|---|
| $0 | 30 years | $382,633 | $0 |
| $100 | 25.1 years | $315,858 | $66,775 |
| $200 | 21.7 years | $269,160 | $113,473 |
| $500 | 15.8 years | $188,203 | $194,430 |
Start making extra payments as early as possible. The same extra payment in year one saves far more interest than in year twenty. Before making extra payments, check for prepayment penalties. Also consider your overall financial situation: high-interest credit card debt or lack of an emergency fund should take priority.
This calculator assumes a fixed interest rate and does not model variable-rate loans. It assumes all payments are made on time and in full. The model may not be appropriate for interest-only loans, balloon payment loans, or lines of credit.
- How does an amortization schedule work?
- Each payment is split into principal and interest. Early payments go mostly to interest; later payments shift to principal.
- How is total interest calculated?
- Total Interest = (Monthly Payment x Number of Payments) - Loan Principal.
- What happens if I make extra payments?
- Extra payments reduce principal faster, decreasing total interest and shortening the loan term.
- What is the difference between fixed and variable rate?
- Fixed rate stays the same for the entire term. Variable rate can change based on market conditions.
- Can this calculator handle different payment frequencies?
- Yes. Supports monthly, bi-weekly, and weekly schedules. More frequent payments reduce total interest.
- Consumer Financial Protection Bureau. "What Is Amortization?" consumerfinance.gov.
- Federal Reserve. "Consumer Guide to Loan Repayment." federalreserve.gov.
- Investopedia. "Loan Amortization Schedule." investopedia.com.
- NerdWallet. "Loan Repayment Calculator Guide." nerdwallet.com.
Last updated: May 12, 2026