Loan Repayment Calculator

We use the standard amortization formula: M = P x r x (1+r)^n / ((1+r)^n - 1), where P is the loan principal, r is the monthly interest rate (annual rate / 12 / 100), and n is the total number of monthly payments. The calculator runs this formula instantly whenever you change an input.

Amortization is the process of spreading a loan into a series of fixed payments over time. Each payment covers both interest and a portion of the principal. Early in the loan, most of each payment goes toward interest; as the balance decreases, more of each payment reduces the principal. We display a full year-by-year amortization table so you can see this shift clearly.

A fixed-rate loan locks in the same interest rate for the entire term, so your monthly payment never changes. A variable (or adjustable) rate can move up or down with market conditions, which means your payment amount may change over time. This tool models a fixed-rate loan. If your rate changes mid-term, re-enter the new rate to see the updated payment.

Extra payments go directly toward reducing the outstanding principal. Because interest is calculated on the remaining balance, a lower balance means less interest accrues each month. Even small extra payments made consistently can shave years off the loan and save a significant amount in total interest.

Interest is charged on the outstanding balance, and the balance is highest at the start of the loan. As you pay down the principal, the interest portion of each payment shrinks and the principal portion grows. The bar chart and amortization table on this page show that crossover visually.

A shorter term means higher monthly payments but substantially less total interest paid over the life of the loan. A longer term lowers your monthly payment, making it more manageable, but you pay more interest overall. We recommend trying both in the calculator to see the trade-off in real numbers.

The interest rate is the cost of borrowing the principal. The APR (Annual Percentage Rate) includes the interest rate plus other costs such as origination fees, closing costs, and mortgage insurance, expressed as a yearly rate. APR gives a more complete picture of the total cost of a loan. This tool uses the base interest rate; compare the result against your lender's quoted APR for a fuller comparison.

Yes. The amortization formula is the same for any fixed-rate instalment loan: mortgages, auto loans, personal loans, and student loans all use it. Enter the loan amount, the annual interest rate your lender quotes, and the repayment term to get your monthly payment and full breakdown.

Most lenders prefer a total debt-to-income (DTI) ratio below 36%, with no more than 28% going to housing expenses. A DTI above 43% usually makes qualifying for a conventional loan difficult. Before borrowing, add up all existing monthly debt payments and compare them to your gross monthly income to see where you stand.

Biweekly payments mean you make 26 half-payments per year instead of 12 full payments, which equals one extra full payment annually. That extra payment goes entirely toward principal, reducing total interest and shortening the loan term. On a 30-year mortgage, biweekly payments can shave roughly 4 to 5 years off the repayment period.

Refinancing is typically worth considering when current market rates are at least 0.75% to 1% lower than your existing rate, or when your credit score has improved enough to qualify for better terms. Factor in closing costs and how long you plan to keep the loan; if the monthly savings recover the refinancing costs within 2 to 3 years, it usually makes financial sense.