The interest rate is the cost of borrowing the principal loan amount. APR (Annual Percentage Rate) includes the interest rate plus other fees and costs associated with the loan, giving you a more complete picture of the loan's cost. For comparison purposes, APR is generally more useful, but for calculation purposes, both can work similarly if fees are minimal.

Biweekly payments result in 26 payments per year (every two weeks), which equals 13 monthly payments instead of 12. This extra payment goes directly toward principal, reducing the loan balance faster and decreasing total interest paid. Over a 30-year mortgage, biweekly payments can save thousands of dollars and pay off the loan 4-5 years earlier.

This depends on your interest rate and investment returns. If your loan interest rate is higher than what you could reasonably expect to earn from investments, paying off the loan is usually better. If you can earn more from investments than your loan interest rate, investing might be better. However, paying off debt provides a guaranteed return (the interest you avoid), while investments carry risk. Consider your risk tolerance, financial goals, and tax implications.

An amortization schedule is a table showing each payment's breakdown over the life of the loan. It shows how much of each payment goes toward principal versus interest, and the remaining loan balance after each payment. Early in the loan, most of your payment goes to interest. As the loan progresses, more goes toward principal. This schedule helps you understand how your loan balance decreases over time.

This depends on your lender's policies. Some lenders allow you to switch to biweekly payments, while others may not. You can always make extra payments manually, which achieves similar results. Check with your lender about their policies regarding payment frequency changes and how they apply extra payments.

The calculator applies your extra payment amount to the principal balance each period. This reduces the principal faster, which means less interest accrues on the remaining balance. The calculator automatically adjusts the payoff timeline and total interest based on these extra payments, showing you exactly how much you'll save.

A fixed-rate loan has an interest rate that stays the same for the entire loan term, so your payment amount never changes. A variable-rate loan (also called an adjustable-rate loan) has an interest rate that can change over time, which means your payment amount can increase or decrease. This calculator assumes a fixed-rate loan. For variable-rate loans, the calculations would need to be adjusted as rates change.

No, this calculator shows only the principal and interest portion of your loan payment. For mortgages, your actual monthly payment may also include property taxes, homeowner's insurance, and possibly private mortgage insurance (PMI) or HOA fees. These additional costs are not included in the calculator's payment amount.