Loan & Mortgage Calculator
Calculate your monthly payment, total interest, and get a complete amortization schedule for any fixed-rate loan or mortgage. Everything runs privately in your browser.
How to use the Loan & Mortgage Calculator
Enter three values: the loan amount (how much you're borrowing), the annual interest rate (the fixed APR from your lender), and the loan term in years. Use the sliders for quick adjustments or type exact values into the number fields.
Click Calculate Payment to instantly see your monthly payment, total amount repaid over the life of the loan, and how much of that total is interest. Scroll down to the amortization schedule to see a month-by-month or year-by-year breakdown of every payment.
How is a monthly mortgage payment calculated?
Monthly payments for fixed-rate loans are calculated using the standard amortization formula:
Where: M = monthly payment, P = loan principal (amount borrowed), r = monthly interest rate (annual rate ÷ 12 ÷ 100), n = total number of monthly payments (years × 12).
This formula is used by banks and lenders worldwide for all fixed-rate installment loans, including mortgages, car loans, and personal loans. The key insight is that early payments are mostly interest — as the balance decreases over time, more of each payment goes toward the principal.
Frequently Asked Questions
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How accurate is this mortgage calculator?
The calculator uses the standard amortization formula identical to those used by banks and mortgage lenders for fixed-rate loans. Results are accurate to the cent for fixed-rate, fully amortizing loans. Results will differ for variable-rate mortgages, interest-only loans, or loans with balloon payments — consult your lender for those.
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Does the payment include taxes and insurance?
No — this calculator computes the principal and interest (P&I) payment only. Your total monthly housing cost will also include property taxes, homeowners insurance, and possibly PMI (private mortgage insurance if your down payment is under 20%). Add those separately based on your specific property and lender requirements.
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What is an amortization schedule?
An amortization schedule is a complete table showing every loan payment across the full term. Each row shows the payment number, how much goes to principal, how much goes to interest, and the remaining balance. In the early years the majority of each payment is interest; toward the end of the term the majority goes to principal.
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Can I use this for a car loan or personal loan?
Yes — the calculator works for any fixed-rate installment loan including car loans, personal loans, and student loans. Simply enter the loan amount, interest rate, and term. The math is identical regardless of what the loan is for.
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How do I calculate how much I save by making extra payments?
The current calculator computes standard scheduled payments. An extra payments feature is on our roadmap. As a quick manual approach: reduce the loan term by the number of years your extra payments would shave off and compare the interest totals between the two calculations.
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Is my data private?
Yes — all calculations run entirely in your browser using JavaScript. No numbers you enter are transmitted to any server or stored anywhere. See our Privacy Policy for details.
Methodology & Limitations
This calculator uses the loan amount, fixed annual interest rate, and term to estimate equal monthly principal-and-interest payments and an amortization schedule.
Limitations: Results are estimates, not a loan offer or financial advice. They may exclude taxes, insurance, mortgage insurance, fees, escrow, rate changes, and lender-specific terms. Confirm costs and disclosures with a lender.
Source: Consumer Financial Protection Bureau: What is a Loan Estimate?.
Prepared and reviewed by MonkeyTactics. Last reviewed .