How to use it
- Enter loan amount, annual interest rate, and loan term in years.
- Type the extra amount you plan to add each month.
- Press Calculate to view interest saved, months shaved off, and the new payoff timeline.
This calculator shows what happens when you add a consistent extra payment to your mortgage. By comparing the standard amortization schedule with the accelerated one, it reveals how much interest you avoid, how many months you eliminate, and the revised payoff period. The numbers matter because even a modest extra amount can translate into thousands of dollars saved and years reclaimed. Read the three results: Interest saved tells you the dollar reduction, Months paid off early shows the time you gain, and New payoff (months) gives the total length of the loan after the extra payment is applied. Use the insight to decide if a budget tweak or occasional bonus should go toward your mortgage.
Pro tips
- Round the extra amount to the nearest $10 for easier budgeting.
- Enter the interest rate as the annual percentage (e.g., 4.5), not the monthly rate.
- If you have a lump‑sum bonus, spread it across months to estimate its impact.
- Confirm the original loan term (15 yr vs 30 yr) matches your loan to avoid skewed results.
Real-life examples
- A homeowner wants to see if adding $200 each month will let them retire debt‑free before age 60.
- A recent graduate with a student‑loan mortgage wonders how a $100 extra payment reduces total interest.
- A couple receiving a $5,000 year‑end bonus wants to know the fastest way to apply it to their mortgage.
Case study
Sarah added $300 extra each month to her 30‑year mortgage. The calculator showed $12,800 saved in interest, 18 months shaved off, and a new payoff of 28.5 years, letting her retire earlier than planned.