Monthly payment and total interest on auto, student and personal loans
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Monthly payment
| Year | Principal paid | Interest paid | Balance |
|---|---|---|---|
| Year 1 | $5,516 | $2,124 | $26,484 |
| Year 2 | $5,926 | $1,714 | $20,558 |
| Year 3 | $6,367 | $1,273 | $14,191 |
| Year 4 | $6,841 | $799 | $7,350 |
| Year 5 | $7,350 | $290 | $0 |
Standard amortization gives the monthly payment on auto, student and personal loans, alongside the declining balance and the interest you accumulate. Add an extra monthly payment to see how much sooner the loan clears.
The scheduled payment pays interest first and then reduces principal. Extra payments reduce principal sooner, so later interest is calculated on a smaller balance; the payoff comparison quantifies that time and cost difference.
Confirm that the lender applies extra money to principal and does not charge a prepayment penalty. Fees included in APR may not be represented in the amortized balance entered here.
Inputs are applied directly to standard finance formulas with monthly compounding where relevant. Results are estimates in the selected currency; they do not include every tax, fee, benefit, market event or local rule. Try a conservative and an optimistic case before making a decision.
Last reviewed: August 2026. Primary references include the IRS 2026, SSA, BLS CPI, U.S. DOL, CFPB.
The amortization formula P × r / (1 − (1+r)^−n), where r is the monthly rate and n the number of months.
Every extra dollar comes straight off principal, so the interest it would have carried disappears too. The earlier you do it, the bigger the saving.
APR includes fees, so it reflects the true annual cost. Compare offers on APR rather than the headline rate.
It is total interest divided by principal. Above about 30%, a shorter term or refinancing is worth a look.
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