Mortgage Calculator
Calculate your monthly mortgage payment, total interest, and view a full amortization schedule.
Optional Monthly Costs
Payment Breakdown
Balance Over Time
Amortization — Annual Breakdown
Year-by-Year Details
| Year | Principal Paid | Interest Paid | Total Payment | Remaining Balance | Cumulative Interest | Equity |
|---|
How It Works
The Mortgage Calculator computes monthly principal-and-interest payments and a full month-by-month amortisation schedule using the standard fixed-rate mortgage formula. Enter the home price, down-payment percentage, annual interest rate, and term in years, and the tool calculates your monthly payment using M = P · r(1+r)^n / ((1+r)^n − 1), where P is the loan principal, r is the monthly interest rate, and n is the total number of payments. Below the summary, an interactive amortisation table shows how each payment splits between interest and principal — interest dominates the first years, then crosses over once the remaining balance has been reduced. A summary panel shows total amount paid over the life of the loan, total interest paid, and the date of the final payment. All numbers update instantly when you change any input, so you can compare scenarios — a higher down payment, a 15-year vs 30-year term, or a half-percent rate difference — side by side. Calculation runs in your browser; nothing about your finances is sent over the network.
Worked Example
Take a $375,000 home with a 20% down payment ($75,000), leaving a $300,000 loan at 6.5% over 30 years. The calculator shows a monthly payment of $1,896.20, total interest of about $382,633 — more than the loan itself — and an 80% loan-to-value ratio. The amortisation chart makes the structure visible: of the first payment, $1,625 is interest and only $271 reduces the balance. Add $100 a month in the extra-payment field and the payoff date moves years earlier, because every extra dollar goes straight to principal.
Use Cases
- Estimating your monthly payment before applying for a mortgage
- Comparing 15-year versus 30-year loan terms
- Seeing how a larger down payment reduces total interest paid
- Planning how extra payments shorten the loan term
Frequently Asked Questions
- Does this include taxes, insurance, or HOA fees?
- No. Only principal and interest. Add property taxes, homeowner's insurance, PMI, and HOA dues separately to get a total monthly housing cost (often called PITI plus).
- How do extra payments affect the loan?
- Every extra dollar paid reduces the principal, which in turn reduces all future interest. A modest monthly overpayment can shave years off a 30-year mortgage.
- What is the difference between APR and interest rate?
- The interest rate is what the formula uses to compute payments. APR includes lender fees amortised over the life of the loan, so it is always slightly higher and is for comparison shopping, not for the payment formula.
- Why does the early payment go almost entirely to interest?
- Because interest accrues on the outstanding principal, which starts at its maximum. As principal shrinks, the interest portion of each payment shrinks too.
- Are my numbers sent anywhere?
- No. The amortisation runs entirely in your browser.