Extra Payment Calculator
See exactly how much time and interest an extra monthly payment can save on any loan or credit card balance.
Your Loan or Debt
How the Extra Payment Calculator works
Every dollar you pay above your required monthly payment goes straight toward reducing your principal balance (assuming no prepayment penalty). A smaller principal means less interest accrues the very next month, which compounds over the life of the loan. This calculator compares your current payoff path against an identical one with your specified extra amount added every month, so you can see the concrete time and dollar impact before committing to it.
Accelerated payoff = amortize(Balance, APR, Payment + Extra)
Interest saved = Baseline interest − Accelerated interest
Why extra payments matter more early
An extra payment made in month one prevents interest from ever accruing on that portion of the balance again — for the entire remaining life of the loan. The same dollar amount paid extra near the end of the loan has almost no effect, since there's little balance left to save interest on. This is why consistently paying extra every month, starting as soon as possible, produces the biggest savings.
Ways to find extra payment money
- Redirect a specific expense — a subscription, a dining-out budget line — permanently to your debt.
- Apply raises and bonuses before they become part of your regular spending.
- Use tax refunds as a single lump-sum extra payment.
- Combine with a strategy: if you have several debts, use the Debt Avalanche or Debt Snowball calculator to decide where extra payments do the most good.
Frequently Asked Questions
On most consumer loans and credit cards, yes — as long as there's no prepayment penalty, any amount you pay above the required monthly payment is applied directly to your principal balance, which reduces the interest that accrues in every future month.
Because interest compounds on your balance every month, even a modest extra payment early in the loan can save a disproportionate amount of interest and shave months or years off your payoff date. The exact amount depends on your balance, rate, and current payment.
Both reduce your balance faster, but consistently adding extra to every monthly payment tends to save more overall, since it reduces the balance that accrues interest sooner and for longer.
If you have multiple debts, directing extra payments at your highest-interest balance first (the avalanche method) generally saves the most money. Use the Debt Avalanche Calculator to model that across several debts at once.