Mortgage Calculator
Down payment, monthly payment and amortization
Mortgage Calculator: the Math of Your Home Purchase
Enter price and down payment — payment, total interest and the full schedule appear.
The most critical question when buying a home isn't 'can I afford the payment?' but 'what will this home cost me in total?'. This tool answers both: enter the home price and your down payment; the loan amount is computed automatically, and your monthly payment, total repayment and total interest burden appear instantly using the standard fixed-payment method. Enter the rate as monthly or yearly, whichever your lender quotes — switching units converts the number automatically. The amortization table breaks every payment into interest and principal with the remaining balance, month by month. Experiment with the down payment and watch the payment and total interest respond — increasing it is often the most profitable 'investment' you can make.
Features
Down Payment Logic
Price − down payment = loan; the ratio is computed.
Monthly Payment
Fixed-installment (annuity) amount, computed precisely.
Amortization Table
Interest, principal and balance for every month.
Monthly / Yearly Rate
Enter the rate in either unit; conversion is automatic.
Mortgage Guide
How it's calculated
- Loan amount = home price − down payment
- Payment = Loan × i ÷ (1 − (1+i)⁻ⁿ)
- Early payments are interest-heavy; principal dominates later
- Lenders typically require a 10-20% down payment
Worth knowing
- A longer term lowers the payment but multiplies total interest
- A bigger down payment cuts total interest directly
- Appraisal, taxes and insurance are extra costs on top
- Compare APR figures when available — quoted rates may exclude fees
Frequently Asked Questions
How is a mortgage payment calculated?
The annuity formula is applied to the loan amount (price − down payment): Payment = Loan × i ÷ (1 − (1+i)⁻ⁿ), with i the monthly rate and n the number of months. The tool does this instantly for any combination.
How much down payment should I make?
Lenders typically require 10-20% of the home value (a loan-to-value cap). Don't settle for the minimum if you can help it: a bigger down payment lowers both the monthly payment and total interest directly — try it in the tool.
Should I choose a long or short term?
A longer term lowers the payment but multiplies interest: stretching the same loan from 10 to 20 years can more than double the total interest. The shortest term your budget comfortably allows is mathematically the cheapest.
Why is interest so high in the early months?
Interest accrues on the full remaining balance each month — and the balance is largest at the start. As the term progresses, the principal share grows. That's also why extra payments in the early years are so effective.
What costs are not included?
Appraisal fees, transfer taxes, homeowner's insurance and possible mortgage insurance aren't included — they vary by country and lender. Budget them separately on top of the down payment.
What happens if I repay early?
You settle the remaining balance and skip the interest of the months that haven't accrued. Some lenders charge an early-repayment fee — check your contract. The balance column shows the amount you'd settle.