Payment Calculator - Free Online Tool

Calculate loan payments, total interest, and full amortization schedule for any loan type

Welcome to our free Payment Calculator, a comprehensive loan analysis tool that helps you calculate regular payment amounts, total interest cost, and a complete amortization schedule for any type of loan. Whether you are evaluating a mortgage, planning an auto loan, comparing personal loan offers, or managing student loan repayment — this calculator provides all the numbers you need to make informed borrowing decisions. Understanding your loan payments before you borrow is one of the most important financial planning steps you can take. Most people focus on the monthly payment amount when evaluating a loan, but the total interest paid over the life of the loan is often far more significant. On a typical 30-year mortgage, the total interest paid can equal or even exceed the original principal borrowed — meaning you effectively pay for the house twice. This calculator makes the total interest cost immediately visible so you can weigh it against the payment you can afford. The calculator offers two calculation modes. In Fixed Term mode, you enter the loan amount, interest rate, and term (in years and months), and the calculator determines your required payment to pay off the loan exactly within that period. This is the standard approach when you have been quoted specific loan terms and want to know your payment amount. In Fixed Payment mode, you enter the loan amount, interest rate, and a payment amount you can afford, and the calculator determines how long it will take to pay off the loan and how much total interest you will pay. This mode is useful for understanding how increasing your payment above the minimum reduces your payoff timeline and interest cost. The calculator supports four loan purpose presets — mortgage, auto, personal loan, and student loan — which pre-fill typical term and rate values as starting points. You can override these values with your actual loan terms. Payment frequency options include monthly, biweekly, and weekly. Biweekly payments (one payment every two weeks, or 26 payments per year) are a popular mortgage strategy: because there are 26 biweekly periods per year rather than 24 (12 monthly payments × 2), biweekly payments result in the equivalent of one extra monthly payment per year. On a 30-year mortgage at 7 percent, this alone can shave roughly 4 to 5 years off the loan term and save tens of thousands of dollars in interest. The extra payment feature lets you model the impact of making additional principal payments on top of your regular payment. Paying an extra $100, $200, or $500 per month toward principal can dramatically reduce total interest paid and shorten the loan term. The results show exactly how much interest you save and how many months sooner you will pay off the loan compared to the original schedule. The full amortization schedule table shows the breakdown of every payment into principal and interest components, as well as the remaining balance after each payment. You can toggle between a detailed monthly view (or per-period view for biweekly/weekly) and a condensed annual summary view. The schedule can be exported to CSV for use in spreadsheets. In the early years of a loan, the majority of each payment goes toward interest; over time, the principal component grows until the final payment is almost entirely principal. All calculations use the standard amortization formula and run entirely in your browser. No data is stored or transmitted.

Understanding Loan Payments and Amortization

What Is Loan Amortization?

Loan amortization is the process of paying off a debt through regular scheduled payments over time. Each payment covers the interest that has accrued since the last payment plus a portion of the principal balance. In a standard fully-amortizing loan, the payment amount is fixed throughout the term, but the split between principal and interest changes with each payment. Early in the loan, most of each payment goes toward interest because the balance is large. As the balance decreases, a growing share of each payment goes toward principal. By the final payment, almost the entire amount is principal. An amortization schedule is a complete table listing every payment, its principal and interest components, and the remaining balance.

How Is the Monthly Payment Calculated?

The standard amortization formula is: Payment = P × [r(1+r)^n] / [(1+r)^n - 1], where P is the principal (loan amount), r is the periodic interest rate (annual rate divided by the number of payments per year), and n is the total number of payments (term in years × payments per year). For example, a $300,000 mortgage at 7% annual interest over 30 years has a monthly rate of 0.5833% and 360 payments. The monthly payment is $300,000 × [0.005833 × (1.005833)^360] / [(1.005833)^360 - 1] = $1,995.91. The total paid over 30 years is $718,526, meaning total interest is $418,526 — 139% of the original loan amount.

Why Loan Analysis Matters

Comparing loan offers by monthly payment alone can be misleading. A longer term reduces the monthly payment but dramatically increases total interest paid. A $300,000 loan at 7%: a 15-year term produces a $2,696 monthly payment and $185,344 total interest; a 30-year term produces a $1,996 payment but $418,527 total interest — more than double the interest for $700 lower monthly payments. Interest rate differences compound over time: just 0.5% lower interest on a 30-year $300,000 mortgage saves approximately $33,000 in total interest. This calculator makes these trade-offs immediately visible so you can weigh the lower payment of a longer term against its true long-term cost.

What This Calculator Does Not Include

This calculator models the core principal and interest payment for a standard fully-amortizing fixed-rate loan. It does not include property taxes or homeowner's insurance in mortgage payment estimates (which together add $200–$500+ per month to the total housing payment). It does not model variable-rate or adjustable-rate mortgages where the interest rate changes after an initial fixed period. It does not include loan origination fees, points, or closing costs in the total cost calculation. For mortgages with less than 20% down payment, private mortgage insurance (PMI) would add an additional monthly cost not shown here. The biweekly payment model assumes 26 equal payments per year — some lenders apply biweekly payments differently.

Loan Payment Formulas

Monthly Payment

M = P × r(1 + r)^n / ((1 + r)^n − 1)

Calculates the fixed periodic payment for a fully amortizing loan, where P is the principal, r is the periodic interest rate (annual rate ÷ payments per year ÷ 100), and n is the total number of payments.

Total Cost of Loan

Total Cost = M × n

The total amount paid over the life of the loan, including both principal and interest. Subtract the original principal to find total interest paid.

Total Interest

Total Interest = (M × n) − P

The total interest paid over the loan's lifetime. On long-term loans, this can equal or exceed the original principal borrowed.

Interest-to-Principal Ratio

Ratio = Total Interest ÷ P

Shows how much interest you pay per dollar borrowed. A ratio of 1.0 means you pay as much in interest as the original loan. Higher ratios indicate costlier loans.

Reference Tables

Monthly Payment per $1,000 Borrowed

Quick reference showing the monthly payment for every $1,000 of loan principal at various interest rates and terms. Multiply by your loan amount in thousands to estimate your payment.

Rate	12 Months	24 Months	36 Months	48 Months	60 Months
3.0%	$84.69	$42.98	$29.08	$22.13	$17.97
4.0%	$85.15	$43.42	$29.52	$22.58	$18.42
5.0%	$85.61	$43.87	$29.97	$23.03	$18.87
6.0%	$86.07	$44.32	$30.42	$23.49	$19.33
7.0%	$86.53	$44.77	$30.88	$23.95	$19.80
8.0%	$86.99	$45.23	$31.34	$24.41	$20.28
9.0%	$87.45	$45.68	$31.80	$24.89	$20.76
10.0%	$87.92	$46.14	$32.27	$25.36	$21.25

Worked Examples

Calculate Payment for a $15,000 Car Loan at 4.9% for 48 Months

Loan amount: $15,000, annual interest rate: 4.9%, term: 48 months.

Convert annual rate to monthly: r = 4.9% ÷ 12 = 0.4083% = 0.004083

Total payments: n = 48

Apply the formula: M = 15,000 × 0.004083 × (1.004083)^48 / ((1.004083)^48 − 1)

(1.004083)^48 = 1.2158

Numerator: 15,000 × 0.004083 × 1.2158 = 74.47

Denominator: 1.2158 − 1 = 0.2158

M = 74.47 ÷ 0.2158 = $345.09

Total paid: $345.09 × 48 = $16,564.32

Total interest: $16,564.32 − $15,000 = $1,564.32

Monthly payment of $345.09 with $1,564.32 in total interest. The interest-to-principal ratio is 0.104, meaning you pay about 10.4 cents in interest for every dollar borrowed.

Compare 36-Month vs 60-Month Terms on a $15,000 Loan at 5.5%

Loan amount: $15,000, annual interest rate: 5.5%. Compare 36-month and 60-month terms.

Monthly rate: r = 5.5% ÷ 12 = 0.004583

36-month payment: M = 15,000 × 0.004583 × (1.004583)^36 / ((1.004583)^36 − 1) = $452.05

36-month total paid: $452.05 × 36 = $16,273.80

36-month total interest: $16,273.80 − $15,000 = $1,273.80

60-month payment: M = 15,000 × 0.004583 × (1.004583)^60 / ((1.004583)^60 − 1) = $286.15

60-month total paid: $286.15 × 60 = $17,169.00

60-month total interest: $17,169.00 − $15,000 = $2,169.00

Difference: $2,169.00 − $1,273.80 = $895.20 more interest for the longer term

Monthly savings with 60-month: $452.05 − $286.15 = $165.90 lower payment

The 36-month term costs $452.05/month with $1,273.80 total interest. The 60-month term is $165.90/month cheaper but costs $895.20 more in total interest — a 70% increase in interest for the longer term.

How to Use the Payment Calculator

Select Your Loan Type and Calculation Mode

Click one of the loan type buttons (Mortgage, Auto, Personal, Student) to pre-fill typical term and rate values as a starting point. Choose Fixed Term mode to calculate your required payment for a given loan term, or Fixed Payment mode to enter an amount you can afford and find out your payoff date and total interest.

Enter Your Loan Details

Enter the loan amount in dollars, the annual interest rate (APR as quoted by your lender), and the loan term in years and months. For Fixed Payment mode, enter your desired payment amount instead of a term. Choose your payment frequency — monthly is standard, but biweekly and weekly options are available and can significantly reduce total interest on longer loans.

Add an Extra Payment to Model Prepayment

In Fixed Term mode, enter an extra payment amount in the Extra Principal Payment field to see how much interest you save and how much sooner you pay off the loan by making additional principal payments each period. This is shown as a separate callout with total interest saved and months saved compared to the standard schedule.

Review the Amortization Schedule

Click Show Schedule to expand the full amortization table, which shows every payment's principal and interest components and remaining balance. Toggle between the by-period detail view and the annual summary view. Use Export CSV to download the complete schedule for use in a spreadsheet, or Print to create a printable record of your loan analysis.

Frequently Asked Questions

How is a monthly loan payment calculated?

Monthly loan payments are calculated using the standard amortization formula: Payment = P × [r(1+r)^n] / [(1+r)^n - 1], where P is the principal balance, r is the monthly interest rate (annual rate divided by 12), and n is the total number of monthly payments (term in years × 12). This formula calculates the fixed payment amount that, if made every month for n months, will exactly pay off the principal plus all accumulated interest. A zero-interest loan simply divides the principal by the number of payments. In the early months of a loan, most of each payment covers interest. As the principal reduces, a larger portion covers principal each month.

What is an amortization schedule?

An amortization schedule is a complete table showing every payment in a loan, broken down into how much goes toward interest and how much goes toward principal, along with the remaining balance after each payment. In a fully amortizing fixed-rate loan, every payment is the same amount, but the split between principal and interest changes with every payment. Early in the loan, most of each payment goes toward interest because the balance is large; in the later years, most of each payment reduces principal. Reviewing an amortization schedule is the most direct way to understand the true cost of a loan over its life and to see how much of each payment is actually reducing what you owe.

How do biweekly payments save money?

Biweekly payments save money by making the equivalent of 13 monthly payments per year instead of 12. When you pay biweekly, you make 26 payments per year (52 weeks ÷ 2). Since each biweekly payment is half the monthly payment amount, 26 × (monthly ÷ 2) = 13 monthly payments per year. This one extra payment per year reduces the principal faster, which reduces the interest that accrues on the remaining balance, which shortens the overall term. On a 30-year $300,000 mortgage at 7%, switching to biweekly payments typically reduces the term by roughly 4 to 5 years and saves approximately $50,000 to $75,000 in total interest. Not all lenders offer true biweekly billing — some collect biweekly but only apply payments monthly.

How much extra should I pay on my loan to save significantly on interest?

Even modest extra principal payments produce significant long-term savings due to compounding interest reduction. On a 30-year $300,000 mortgage at 7%: an extra $100/month saves approximately $43,000 in interest and pays off 6 years early; an extra $200/month saves approximately $72,000 and pays off 8 years early; an extra $500/month saves approximately $124,000 and pays off 12 years early. The key insight is that extra payments made early in the loan term have the greatest impact because they reduce the balance from which future interest accrues. Use this calculator's extra payment field to model specific scenarios for your loan. The interest saved consistently exceeds the extra payments made due to the compounding reduction in interest charges.

What is the difference between APR and interest rate?

The interest rate (also called the note rate or nominal rate) is the base cost of borrowing expressed as an annual percentage of the outstanding balance. The APR (Annual Percentage Rate) is a broader measure that includes the interest rate plus certain fees and costs associated with the loan — such as origination fees, mortgage broker fees, and other lender charges — expressed as an annual percentage. For comparing loan offers, the APR is more informative because it captures the full cost of borrowing, not just the stated interest rate. However, APR calculations can vary by lender as to which fees are included. This calculator uses the rate you enter as the nominal interest rate for payment calculations — if you have only been given an APR that includes fees, the actual payment calculation should use the note rate.

What is Fixed Payment mode used for?

Fixed Payment mode is used when you have a specific payment amount you can afford and want to understand the borrowing capacity or payoff timeline that payment creates. Instead of asking 'what is my payment for this loan?', Fixed Payment mode asks 'given this payment amount, how long will this loan take to pay off and how much total interest will I pay?' This is useful for budgeting-driven borrowing decisions, for modeling different payoff speeds on an existing loan, and for understanding the relationship between payment amount and loan cost. The calculator also shows the maximum loan amount that a given payment could service over a standard 30-year term — useful as a rough affordability check before discussing specific loan amounts with a lender.