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Calculate the total interest you will pay over the life of a loan. Enter principal, rate, and term to see how much of your money goes toward interest charges.
Total interest is the difference between what you repay and what you borrowed. First, calculate the monthly payment using M = P × [r(1+r)^n] / [(1+r)^n − 1]. Then: Total Interest = (M × n) − P. For a $30,000 loan at 9% APR over 5 years: M = $622.75, total repaid = $37,365, and total interest = $7,365. This means 19.6% of your total payments go to interest alone.
Three strategies to minimize interest: 1) Choose a shorter term — a 3-year term vs. 5-year term on $30,000 at 9% saves $4,209 in interest. 2) Make extra principal payments — even $50/month extra significantly reduces the balance faster. 3) Refinance to a lower rate — dropping from 9% to 6% on the same loan saves $2,518 in interest over 5 years.
On a $300,000 mortgage at 6.5% for 30 years, you will pay approximately $382,633 in total interest — more than the original loan amount. This is why even small rate differences matter significantly over long terms.
Yes. Biweekly payments (half the monthly payment every two weeks) result in 26 half-payments per year — equivalent to 13 full monthly payments instead of 12. This extra payment goes entirely to principal, reducing total interest and shortening the loan term.
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