Extra Payment Impact Calculator
Show time and interest saved by making extra payments.
Adding extra principal to loan payments reduces total interest and shortens payoff. Even $50–100 extra per month can save thousands and cut years off a loan. This calculator compares standard payoff vs payoff with extra payments so you can see the impact.
Inputs
Results
Standard: 60 mo, $4,661 interest
With extra: 48 mo, $3,650 interest
Saved: $1,011 and 12 months
Insights
Formula
Standard: amortization with regular payment With extra: apply extra to principal each month, recalc payoff
Input Definitions
What does each input mean?
- Loan amount
- Principal—the amount borrowed.
- APR
- Annual percentage rate on the loan.
- Term
- Original loan length in months.
- Extra payment/month
- Additional amount applied to principal each month. Reduces balance faster and cuts total interest.
Related Calculators
What an Extra $100 a Month Does to Your Loan
Extra payments toward a loan don’t just save you interest — they compound: each extra dollar reduces principal, which reduces the interest calculated next month, which means even more of subsequent payments go toward principal. This calculator makes that effect visible, showing you exactly how many months you’ll shave off your loan term and how much total interest you’ll avoid by adding even a modest extra payment each month.
It’s particularly valuable for mortgage holders, business loan borrowers, and anyone managing an auto or personal loan who has occasional surplus cash and wants to use it strategically. Run several scenarios — $50, $100, $200 extra per month — to find the sweet spot where the payoff acceleration is meaningful without straining your cash flow.