Loan Payment Calculator

Payment from the standard formula at the chosen frequency; biweekly pays half the monthly amount every fortnight, adding one extra payment a year.

Your payment, and how to shrink the total

The payment itself comes straight from the loan’s size, rate and term. The interesting part is what you can do to the total: a level monthly payment over a long term piles up a great deal of interest, but small changes to how and when you pay can cut years and a surprising sum off it. This calculator shows the payment, the totals, and — the moment you change the frequency or add anything extra — how much you save against a plain monthly plan.

The chart makes it visual: your balance falling over time, with the accelerated curve laid over the standard one. The horizontal gap between where the two curves hit zero is the time you have shaved off.

Worked example — $300,000 at 6% over 30 years: Monthly payment ≈ $1,799, with about $347,500 of interest over the full term. Switch to biweekly ($899 every two weeks) and the loan clears years early, saving tens of thousands in interest.

The biweekly trick

Paying biweekly is the simplest acceleration there is. Instead of one monthly payment, you pay half of it every two weeks. Because there are 26 fortnights in a year — not 24 — you end up making the equivalent of 13 monthly payments a year instead of 12. That one extra payment goes entirely to principal, and over a long loan it clears the debt several years early and saves a large slice of interest.

Weekly works the same way, just in smaller, more frequent instalments. Neither requires finding much more money — only paying the same annual amount split differently. The calculator shows the interest saved and the years cut for whichever frequency you pick.

Extra payments, fees and real cost

On top of the frequency, you can add a recurring extra payment or a one-time lump. Both attack the principal directly, so they cut the balance the interest is charged on — and because early balances are largest, an extra payment now saves far more than the same amount later. The calculator re-runs the schedule and reports the new payoff and the interest saved.

A processing fee raises the true cost of borrowing, shown as an effective rate (APR) above the headline. And because money loses value over time, the calculator can express the total of your future payments in today’s money — the real cost — which is always less than the nominal total.