Loan Payment Calculator

About the Loan Payment Calculator

When you borrow money for a car repair, a home improvement project, debt consolidation, or a piece of business equipment, the lender usually quotes a rate and a term, and you are left to work out whether the monthly payment fits your budget. This calculator does that work for any fixed-rate installment loan. Enter the amount borrowed, the annual interest rate, and the term in months, and it returns the level monthly payment, the total interest you will pay, and the total you will have repaid by the final installment.

The math is the standard amortization formula used by banks and credit unions: the payment is set so that equal monthly installments pay off both the interest accrued each month and, gradually, the principal. Because it uses a single constant rate, it models personal loans, many student loans, equipment financing, and any other loan with a fixed rate and fixed schedule. It will not model a variable rate, a balloon payment, interest-only periods, or a loan where interest is charged daily on an irregular schedule.

The most valuable thing the tool shows is the tradeoff between term and cost. Stretching a loan over more months always lowers the monthly payment, but it raises the total interest, sometimes by thousands of dollars. Running two or three terms side by side, using the same amount and rate, lets you pick the shortest term whose payment you can reliably afford, rather than defaulting to whatever monthly figure a lender or dealer suggests.

When to Use It

How to Use It, Step by Step

1. Enter the Loan amount in dollars. Use the amount you will actually receive and owe, and remember that some lenders subtract origination fees from the proceeds, which changes your effective borrowing.
2. Enter the Interest rate as an annual percentage, for example 7.5. Take it from the lender's offer or loan estimate. The tool accepts rates from 0 up to 40 percent.
3. Enter the Loan term in months, not years. A three-year loan is 36 months and a five-year loan is 60 months. The field accepts values from 1 to 480.
4. Press the calculate button to see the Monthly payment, Total interest paid, and Total amount repaid.
5. Compare the Monthly payment with your budget after rent or mortgage, utilities, food, and existing debts, not with your gross income.
6. Rerun the calculation with a shorter and a longer term, keeping the amount and rate the same, to see how the payment and the total interest trade off against each other.
7. Rerun it at one or two different rates if you are shopping around, so you can see how much a lower quote saves before you commit to a lender.
8. If a lender charges an origination fee or other upfront costs, ask for the annual percentage rate and compare offers using that figure as well as the stated rate.

Understanding Your Results

The Monthly payment is the fixed installment you would pay each month under a standard amortization schedule. Because it is calculated with full precision and rounded only for display, the total on the screen can differ by a few cents or dollars from the rounded monthly payment multiplied by the number of months. That is normal rounding and not an error in the calculation.

Total interest paid equals all of your payments added together minus the original loan amount. Total amount repaid is the sum of all payments, which is the loan amount plus total interest. For a sanity check, a rough guide is that at 0 percent, interest is zero and the payment is just the amount divided by the months. As the rate or term rises, the interest total climbs; longer terms increase it much faster than people expect.

Once you have the figures, check them against a realistic budget and consider the cost of waiting versus borrowing. Compare the total repaid with the item's price, ask whether a smaller loan or a down payment would reduce interest, and confirm whether the lender allows early payoff without a penalty. If the payment feels tight at the shortest term you can manage, consider borrowing less rather than extending the term.

More Worked Examples

Tips for Better Results

• Always convert years to months before entering the term. Typing 5 for a five-year loan is read as a five-month loan and produces a payment many times too large.
• Compare loans using total interest and total repaid, not just the monthly payment, since a lower payment from a longer term can easily hide a more expensive loan.
• Ask lenders for the annual percentage rate as well as the interest rate, because origination fees and other charges are folded into APR and make offers easier to compare.
• If you have no prepayment penalty, adding even a modest extra amount to each payment can shorten the loan and cut interest. Confirm with the lender that extra money is applied to principal.
• Try your payment at a rate one or two points higher than quoted if your offer is not final. A pre-qualification quote can change once the lender checks your credit and income.
• Do not borrow the maximum you qualify for just because the payment looks small. Choose the amount you need, then pick the shortest term your budget supports comfortably.

Common Mistakes to Avoid

• Entering the term in years. The field is in months, so convert first; a 3-year loan is 36 months, and entering 3 turns it into a 3-month loan and the payment comes out roughly ten times too high.
• Ignoring fees. This calculator covers principal and interest only, so origination fees, late fees, or insurance add-ons will make your actual cost higher than shown.
• Comparing loans only by monthly payment. A cheaper payment on a longer term often means much more total interest, so compare the total repaid on each offer.
• Using a variable-rate loan's starting rate as if it were permanent. This tool assumes the rate never changes, so a variable rate that adjusts upward will raise your payment.
• Treating the estimate as a binding quote. Use it for planning, then rely on the lender's disclosure documents for the exact payment, APR, and any penalties.

Assumptions and Limits

• The calculator assumes a fixed interest rate, equal monthly payments, and interest that compounds monthly using the annual rate divided by 12. Loans that charge simple daily interest or use a different day-count method can differ slightly.
• Fees, closing costs, insurance, and penalties are not included. If a lender deducts an origination fee from the amount you receive, your effective rate is higher than the stated rate.
• Figures are rounded to cents for display. The total repaid is computed from the unrounded payment, so it may differ by a few cents or dollars from the displayed payment times the number of months.
• For significant borrowing decisions, especially secured loans or loans against property, review the lender's terms and consider speaking with a licensed financial professional or nonprofit credit counselor.

Key Terms

Installment loan

A loan repaid in equal scheduled payments over a set number of months, such as a personal loan, car loan, or student loan.

APR

Annual percentage rate. It expresses the yearly cost of borrowing as a percentage and typically includes certain fees as well as interest, making offers easier to compare.

Amortization

The gradual repayment of a loan through scheduled payments, where each payment covers that month's interest and the remainder reduces the principal.

Principal

The amount you borrowed and still owe, not counting interest. Each payment lowers the principal by a little more than the one before.

Origination fee

A fee some lenders charge for processing a loan, often a percentage of the amount borrowed and sometimes deducted from the money you receive.

Prepayment penalty

A charge some loans apply if you pay off the balance early. Many consumer loans have none, but it is worth checking the contract before signing.