Mortgage calculator

See the monthly cost of a home loan and where every payment goes over the term.

Formula Finance

Monthly payment

Principal and interest: US$1,918.56
Loan amount: US$320,000.00
Down payment: US$80,000.00
Total interest: US$370,682.20
Total of monthly payments: US$690,682.20

TotalUS$690,682.20

Principal: US$320,000.0046.3%
Total interest: US$370,682.2053.7%

How it works

The loan is the price minus the down payment. It is repaid in equal monthly instalments of principal and interest, with interest at the annual rate divided by 12 on the remaining balance.

If you add property tax, insurance or fees, their monthly share is added to give the full monthly cost. These vary by country and property, so use your own figures; they are left out by default.

The result assumes a fixed rate for the whole term. Variable, tracker or interest-only mortgages, arrangement fees and mortgage insurance are not included.

Formula

Loan L = price − down payment
r = annual rate ÷ 12 ÷ 100,  n = years × 12
P&I = L × r ÷ (1 − (1 + r)^−n)
Monthly = P&I + tax ÷ 12 + insurance ÷ 12 + fees

Worked example

A 400,000 home with 20% down (80,000) leaves a 320,000 loan. At 6% over 30 years, principal and interest are 1,918.56 a month and total interest is 370,682.20. Adding 4,800 a year of property tax and 1,200 of insurance makes it 2,418.56 a month.

Questions people ask

How much does a bigger down payment help?

Every unit you put down is a unit you don’t borrow, so the payment and interest fall in proportion. Some lenders also offer better rates at lower loan-to-value ratios.

Why is the total interest so high?

Over 25 or 30 years interest is charged on a large balance for a long time. A shorter term raises the payment but cuts the total interest sharply.

Does this work outside the US?

Yes. Repayment mortgages work the same way everywhere; leave the tax, insurance and fee fields empty if they are not paid with your mortgage.