# Mortgage Calculator

Calculate your monthly mortgage payment, total interest, and loan cost. Free online mortgage calculator with support for different loan terms and rates.

## What this calculates

Use our free mortgage calculator to estimate your monthly home loan payment. Enter your home price, down payment, interest rate, and loan term to instantly see your monthly obligation, total interest paid, and total cost of your mortgage over its full term.

## Inputs

- **Home Price / Loan Amount** ($) — min 0 — The total amount you plan to borrow.
- **Down Payment** ($) — min 0 — Amount paid upfront. Typically 3-20% of home price.
- **Annual Interest Rate** (%) — min 0, max 30 — The yearly interest rate on your mortgage.
- **Loan Term** — options: 10 years, 15 years, 20 years, 25 years, 30 years — The length of your mortgage in years.

## Outputs

- **Monthly Payment** — formatted as currency — Your estimated monthly mortgage payment.
- **Total Interest Paid** — formatted as currency — The total amount of interest over the life of the loan.
- **Total Cost of Loan** — formatted as currency — The total amount you will pay including principal and interest.
- **Loan Amount** — formatted as currency — Home price minus down payment.

## Details

A mortgage is a loan used to purchase real estate, where the property itself serves as collateral. The most common mortgage types in the United States are 15-year and 30-year fixed-rate mortgages, though adjustable-rate mortgages (ARMs) are also available.

The monthly payment on a fixed-rate mortgage is calculated using the standard amortization formula: M = P[r(1+r)^n] / [(1+r)^n - 1], where P is the loan principal, r is the monthly interest rate (annual rate divided by 12), and n is the total number of monthly payments.

Your monthly mortgage payment consists of principal and interest (P&I). Keep in mind that your actual monthly housing cost may also include property taxes, homeowners insurance, and private mortgage insurance (PMI) if your down payment is less than 20%.

A larger down payment reduces your loan amount, which lowers both your monthly payment and total interest paid. Even a small reduction in interest rate can save tens of thousands of dollars over the life of a 30-year mortgage. For example, on a $240,000 loan, the difference between a 6.0% and 6.5% rate is approximately $34,500 in total interest over 30 years.

## Frequently Asked Questions

**Q: How is a monthly mortgage payment calculated?**

A: The monthly mortgage payment is calculated using the amortization formula: M = P[r(1+r)^n] / [(1+r)^n - 1]. P is the loan principal (home price minus down payment), r is the monthly interest rate (annual rate / 12 / 100), and n is the total number of monthly payments (years times 12). This formula ensures equal monthly payments over the full loan term, with the proportion going to interest decreasing over time as the principal balance is paid down.

**Q: What is the difference between a 15-year and 30-year mortgage?**

A: A 15-year mortgage has higher monthly payments but a significantly lower total interest cost. A 30-year mortgage spreads payments over a longer period, resulting in lower monthly payments but much more interest paid over the life of the loan. For example, a $240,000 loan at 6.5% costs about $1,517/month over 30 years (total interest ~$306,000) versus $2,091/month over 15 years (total interest ~$136,000).

**Q: How much down payment do I need for a mortgage?**

A: Conventional mortgages typically require 3-20% down. FHA loans require as little as 3.5% down. VA and USDA loans may allow 0% down for eligible borrowers. Putting down at least 20% eliminates the requirement for private mortgage insurance (PMI), which can add $50-$200+ per month to your payment. A larger down payment also means a smaller loan, lower monthly payments, and less total interest paid.

**Q: Does this calculator include taxes and insurance?**

A: This calculator computes principal and interest (P&I) only. Your actual monthly housing cost will also include property taxes, homeowners insurance, and possibly PMI or HOA fees. As a rough estimate, property taxes and insurance typically add 1-3% of the home value per year. You can expect your total monthly cost to be 20-40% higher than the P&I amount shown.

**Q: How does interest rate affect total mortgage cost?**

A: Interest rate has an enormous impact on the total cost of a mortgage. On a $300,000 30-year loan, each 0.5% increase in the rate adds roughly $30,000-$35,000 to the total interest paid over the life of the loan. This is why even small improvements in your interest rate, such as through buying discount points or improving your credit score, can lead to substantial long-term savings.

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Source: https://vastcalc.com/calculators/finance/mortgage
Category: Finance
Last updated: 2026-04-21