See how extra payments can save you thousands
Adjust your mortgage parameters
Adding $200/month saves you $103,449 in interest and pays off your mortgage 6 years and 11 months earlier!
Payoff strategy
This tool shows how recurring or one-time principal prepayments can shorten your loan term and reduce lifetime interest.
Typical Use
About 1 minute
Best For
Testing payoff strategies before committing extra cash each month
Main Output
Interest savings and earlier payoff estimates
Built Around
Standard mortgage math and planning assumptions
Source notes and methodology details are available on our references page.
Our calculations follow the Truth in Lending Act (TILA) guidelines and use standard financial formulas employed by major lending institutions.
Monthly Payment Calculation
M = P[r(1+r)^n]/[(1+r)^n-1]Where M = monthly payment, P = principal loan amount, r = monthly interest rate, n = number of payments
Amortization Schedule
Standard declining balance methodEach payment is split between interest (calculated on remaining balance) and principal reduction
APR Estimation
Includes interest + fees over loan termAnnual Percentage Rate calculations include all financing charges as required by Truth in Lending Act (TILA)
Content is published under the MortgageCalcMaster editorial team workflow, currently led by the site operator, reviewed against public mortgage and consumer-finance sources, and updated when assumptions, formulas, or product behavior materially change.
Last reviewed: March 2026. All calculators and guides are intended for education and planning. They do not replace lender disclosures or advice from licensed professionals. Learn more about our editorial process
Enter your current loan details: balance, interest rate, and remaining term.
Input your current monthly payment amount.
Add the extra amount you plan to pay each month toward principal.
Review the results to see how many years you'll save and total interest reduction.
Try different scenarios by adjusting the extra payment amount to find what works for your budget.
Consider the 'One-time Payment' option to see the impact of applying a lump sum.
This calculator provides estimates based on standard formulas. Actual loan terms may vary based on your credit score, lender policies, and market conditions. Always consult with a qualified mortgage professional before making financial decisions.
Use these guides to decide when paying extra principal beats keeping cash, refinancing, or investing elsewhere.
Compare recurring overpayments, lump sums, and payoff strategy tradeoffs.
See why early extra payments usually save more interest than later ones.
Check whether a refinance helps more than making larger principal payments.
FAQ
These answers explain the assumptions behind the calculator so users can interpret the output with the right context.
Extra payments go directly toward your principal balance, reducing the amount of interest you pay over the life of the loan. Even small additional payments can save tens of thousands in interest and shave years off your mortgage term.
Extra payments make sense if you have an emergency fund, no high-interest debt, and plan to stay in your home long-term. Compare your mortgage rate to potential investment returns to decide the best use of extra funds.
Popular strategies include rounding up payments, making bi-weekly payments (resulting in one extra payment per year), applying annual bonuses or tax refunds, or adding a fixed extra amount each month. Always specify payments should go to principal only.