Loan Calculator

1. Enter the total loan amount in dollars.
2. Enter the annual interest rate as a percentage (e.g., 5.0 for 5%).
3. Set the loan term and toggle between years and months using the buttons. The value converts automatically when you switch.
4. View your monthly payment, total payment, and total interest instantly.
5. Click "Amortization Schedule" to see the full month-by-month payment breakdown with principal, interest, and remaining balance.

What Is a Loan?

A loan is a financial agreement in which a lender provides a borrower with a sum of money that must be repaid over time, typically with interest. Fixed-rate installment loans are the most common type, featuring equal monthly payments over a set period. Each payment includes both a principal portion (paying down the balance) and an interest portion (the cost of borrowing). This calculator works for personal loans, auto loans, student loans, and any other fixed-rate installment loan. Understanding how loans are structured helps you compare offers, negotiate better terms, and plan your repayment strategy effectively.

How Loan Payments Are Calculated

Monthly loan payments are computed using the amortization formula: M = P[r(1+r)^n] / [(1+r)^n - 1], where P is the loan amount, r is the monthly interest rate (annual rate divided by 12), and n is the total number of monthly payments. This formula ensures that your payment stays the same each month, even though the split between principal and interest changes over time. In the early months, interest makes up a larger portion of your payment because the outstanding balance is higher. As you pay down the principal, less interest accrues and more of each payment reduces the balance.

Common Use Cases

• Estimating monthly payments before applying for a personal or auto loan
• Comparing multiple loan offers with different rates and terms
• Calculating total interest paid over the life of the loan to understand the true cost
• Reviewing the amortization schedule to see how principal and interest shift over time
• Deciding between a shorter term (lower total cost) and a longer term (lower monthly payment)
• Planning how extra payments can reduce interest and shorten the loan term

Fixed Rate vs. Variable Rate Loans

Fixed-rate loans lock your interest rate for the entire term, so your monthly payment never changes. This predictability makes budgeting straightforward and protects you from rising interest rates. Variable-rate loans (also called adjustable-rate loans) typically start with a lower introductory rate but can increase or decrease based on market conditions. During periods of falling rates, a variable-rate loan can save you money. However, if rates rise, your payment can increase substantially, sometimes by hundreds of dollars per month.

For long-term loans (5 years or more), most borrowers prefer the certainty of a fixed rate. Variable rates may make sense for short-term borrowing or if you plan to pay off the loan quickly before rate adjustments take effect. When comparing offers, always look beyond the monthly payment. The total interest paid over the life of the loan reveals the true cost of borrowing. A lower interest rate or shorter term can save you thousands of dollars, even if the monthly payment is slightly higher. On a $30,000 loan at 6% over 5 years, your first monthly payment of $580 includes $150 in interest and $430 toward principal. By the final year, nearly the entire payment goes to principal because the remaining balance is so low.

Explore home-specific financing with the Mortgage Calculator, plan your vehicle purchase with the Auto Loan Calculator, or build a debt elimination plan with the Debt Payoff Calculator.