Work out the monthly payment, total interest, and total cost for any fixed-rate loan.
This uses the standard fixed-rate amortization formula: your loan amount, annual interest rate, and term are combined to spread principal and interest evenly across every monthly payment. Upfront fees are shown separately since they're usually paid once, not financed into the monthly amount.
Actual lender quotes may differ slightly based on how they round, compound interest, or bundle in extra charges.
Enter your loan amount, annual interest rate, and loan term (in months or years, depending on the toggle), plus any upfront fees your lender charges. Click Calculate to see your fixed monthly payment, the total interest you'll pay over the life of the loan, and the overall total cost. Adjusting any single input — a slightly lower rate, a shorter term, a smaller loan amount — instantly recalculates the result, which makes this tool useful for comparing multiple loan offers side by side before committing to one.
A fixed-rate loan uses this formula to calculate the monthly payment: M = P × [r(1+r)^n] / [(1+r)^n − 1], where P is the loan principal, r is the monthly interest rate (annual rate divided by 12), and n is the total number of monthly payments. This formula guarantees that every payment is exactly the same amount, but the mix inside each payment shifts over time — early payments are weighted heavily toward interest, and later payments shift toward principal, even though the total payment stays flat. This is why paying off a loan early saves more in interest than the payment amount alone might suggest.
Stretching a loan over a longer term lowers the monthly payment, but it significantly increases the total interest paid, because interest accrues on the outstanding balance for a longer period. For example, a $20,000 loan at 6% interest costs noticeably less in total interest over 3 years than the same loan spread over 6 years, even though the 6-year version has a lower monthly payment. This tradeoff — lower monthly payment vs. lower total cost — is one of the most important decisions to weigh when comparing loan offers, and it's exactly what this calculator is built to show clearly.
Even a small difference in interest rate can meaningfully change your total cost, especially on larger loans or longer terms. A 1% difference in rate on a $30,000, 5-year loan can shift total interest by hundreds of dollars. This is why it's worth shopping around and comparing rates from multiple lenders rather than accepting the first offer — a lower advertised rate from one lender might also come with different fees, so comparing the full picture (rate, term, and fees together) using a calculator like this one gives a fairer comparison than looking at any single number alone.
Many loans include upfront costs beyond the interest rate — origination fees, processing fees, or closing costs. These are typically paid once, either out of pocket or rolled into the loan amount, rather than spread across every monthly payment. Because these fees add to the real cost of borrowing without changing the advertised interest rate, lenders are often required to disclose an APR (Annual Percentage Rate), which combines the interest rate and most fees into a single number that better reflects the loan's true cost. When comparing two loans, comparing APRs — not just the interest rate — gives a more accurate picture of which is actually cheaper.
Making extra payments toward principal — even small, occasional ones — can meaningfully reduce both your total interest paid and how long it takes to pay off the loan, since every extra dollar toward principal stops accruing interest immediately. For example, adding a modest extra payment each month on a multi-year loan can shave months or even years off the payoff timeline. Before making extra payments a habit, it's worth checking your loan agreement for prepayment penalties, which some lenders charge if a loan is paid off faster than the original schedule, though these are becoming less common on many consumer loan types.
Why is my actual lender's payment slightly different from this calculator's result? Lenders sometimes round differently, use slightly different day-count conventions, or bundle additional fees into the monthly payment rather than charging them upfront. This calculator gives a close, standard estimate, but always confirm the exact figure with your lender before signing.
Does paying extra toward principal reduce my monthly payment? Not usually — extra payments typically reduce the loan balance and shorten the payoff timeline, but the required monthly payment usually stays the same unless you specifically request loan recasting from your lender.
What's the difference between a fixed-rate and variable-rate loan? This calculator assumes a fixed rate, meaning the interest rate and payment stay the same for the life of the loan. A variable-rate loan's rate (and therefore payment) can change over time based on market conditions.
Is a shorter loan term always the better choice? It depends on your priorities — a shorter term means less total interest but a higher monthly payment, while a longer term means a lower monthly payment but more total interest. There's no universally "right" answer; it depends on your monthly budget and financial goals.
Can I compare two different loan offers side by side? Run the calculator once per offer, noting each result, then compare the monthly payment and total interest figures directly against each other.
Is a co-signer's credit used in these calculations? No — this calculator only uses the loan amount, rate, and term you enter. Your actual approved rate may depend on your credit profile or a co-signer's, which a lender determines separately.
What loan types does this calculator work for? It works for any fixed-rate, fixed-term loan — personal loans, auto loans, and similar installment loans all follow the same amortization math this tool uses.
Does this calculator work for loans with balloon payments? No — it assumes a standard fully-amortizing loan where the balance reaches zero at the end of the term, not a loan structure with a large final lump-sum payment.
Last reviewed by Mehmed on July 11, 2026.