Everything about the
Loan Calculator.

Forgely's calculator runs entirely in your browser using the standard amortization formula. You enter your loan amount, down payment, interest rate, loan term, and an optional extra monthly payment. The calculator computes your monthly payment, the total interest you will pay over the life of the loan, your exact payoff time, and a full year-by-year amortization breakdown. All math happens locally — no data is sent to a server.

The calculator uses the standard fixed-rate amortization formula: M = P × r × (1+r)^n ÷ ((1+r)^n − 1). M is the monthly payment, P is the financed principal (loan amount minus down payment), r is the monthly interest rate (APR ÷ 100 ÷ 12), and n is the total number of monthly payments (term × 12). For 0% interest, the payment simplifies to P ÷ n.

Interest is calculated each month on your remaining balance. At the start of a long mortgage, your balance is highest — so the interest charge is largest. As your balance slowly decreases, less interest accrues each month and more of each fixed payment reduces principal. This is amortization, and it explains why the early years of a 30-year mortgage feel like slow progress toward equity.

For a standard fixed-rate loan, this calculator is mathematically exact. Results will match your lender's payment schedule to the penny, provided you enter the same rate and term. Accuracy depends entirely on your inputs — use your actual offered interest rate, not an estimate. The calculator does not account for closing costs, origination fees, prepayment penalties, or variable-rate adjustments.

The interest rate (note rate) is the base annual cost of borrowing, used to calculate your monthly payment. The APR (Annual Percentage Rate) includes the interest rate plus most lender fees rolled into an annual percentage — making it more useful for comparing loan offers across lenders. This calculator uses your entered rate as the nominal annual rate compounded monthly. For the most accurate monthly payment, enter the interest rate; for comparing total cost across lenders, enter the APR.

A down payment is an upfront cash payment you make when purchasing a home or vehicle. The calculator subtracts your down payment from the loan amount to get the financed principal — the amount on which interest is charged. A larger down payment means a smaller principal, a lower monthly payment, and far less total interest over the life of the loan.

A 30-year mortgage has lower monthly payments but you pay significantly more total interest. A 15-year mortgage has higher monthly payments but a lower interest rate (typically 0.5%–0.75% lower) and far less total interest. Use the calculator to compare: click 15 yr versus 30 yr and see the difference in total interest paid. If you can comfortably afford the 15-year payment, the long-term savings are usually substantial.

An amortization schedule shows how each payment is split between interest and principal, and the remaining balance after each payment. In the early years, most of each payment is interest. Over time, more goes to principal. Expand the 'Yearly amortization breakdown' section to see this by year for your specific loan.

The horizontal split bar shows the proportion of your total repayment going to principal (green, the amount you borrowed) versus interest (orange, the cost of borrowing). On a 30-year mortgage at a moderate rate, total interest often exceeds the original loan amount. The legend shows exact dollar amounts so you can see at a glance how much of your payments are interest.

Payoff time is how long it will take to fully pay off your loan. For a standard loan with no extra payment, payoff time equals the term. When you add an extra monthly payment, the calculator finds the actual month the balance reaches zero — which will be shorter than the original term. The difference is the time saved.

No — it computes principal and interest only. A real mortgage payment often also includes property taxes, homeowner's insurance, and PMI (if your down payment is less than 20%), collected by your lender in escrow. These vary by location and lender. Contact your lender for a full PITI quote including all components.

Extra payments go directly to reducing your principal. A lower principal means less interest accrues next month, which accelerates payoff in a compounding way. The calculator runs a full month-by-month amortization both with and without your extra payment, then shows the exact interest saved and months eliminated. Even $100–$200 extra per month can save tens of thousands of dollars and years off a 30-year mortgage.

The calculator runs two complete month-by-month amortization simulations — one with your extra payment applied each month, one without. It tracks total interest in both cases and subtracts them. The difference is the interest saved. This is why the number is exact rather than an approximation.

This calculator assumes you make the same extra payment every month for the life of the loan. Occasional extra payments still help but the amount of savings will be less than shown. To model an occasional lump sum, you could divide your annual extra payment by 12 and enter that as a monthly figure to get an approximate estimate.

Yes. For a car loan, enter the vehicle price (or financed amount) as the loan amount, your actual down payment, the offered interest rate, and choose the term (typically 3–7 years using a custom entry if needed). Leave the standard buttons for 10/15/20/30 and use the term that matches your actual loan. The monthly payment and total interest will be accurate for any fixed-rate amortizing auto loan.

Yes for fixed-rate amortizing loans. Enter the loan amount, leave down payment at zero, enter the interest rate and term. Note that some federal student loans use income-driven repayment plans that are not standard amortization — this calculator covers only fixed-rate amortizing loans where the payment is the same every month.

No. Adjustable-rate mortgages have a rate that changes after an initial fixed period. This calculator handles only fixed-rate loans where the rate stays constant for the entire term. For ARMs, you can use this calculator to estimate the initial fixed-rate period, but the payment will change when the rate adjusts.

A common guideline is that your total housing payment (principal, interest, taxes, and insurance) should not exceed 28% of your gross monthly income. Enter different loan amounts in the calculator to see which monthly P&I payment stays within 28% of your monthly income. For a precise affordability analysis, a licensed mortgage lender can review your income, debts, and credit to give a pre-approval amount.

Yes, completely free. No account, no email, no signup required. There is no word limit, no usage cap, and no paywall. All calculations run locally in your browser.

No. All calculation happens in JavaScript in your browser. No loan amounts, interest rates, or results are sent to Forgely's servers or any third party. Your financial information stays entirely on your device.