Loan / Mortgage Calculator
Your monthly payment and total interest for a fixed-rate loan or mortgage.
How this is calculated
This uses the standard fixed-rate amortization formula: the same monthly payment every month for the full term, made up of a changing mix of interest and principal — mostly interest at the start, mostly principal by the end.
Example: a $200,000 loan at 4% over 30 years → a monthly payment of about $954.83, totalling about $343,739 paid — roughly $143,739 in interest over the life of the loan.
How rate and term change the total cost
- $20,000 car loan, 6% over 5 years: about $386.66/month, ≈$3,199 total interest.
- $200,000 mortgage, 4% over 30 years: about $954.83/month, ≈$143,739 total interest.
- Same mortgage over 15 years instead of 30: a noticeably higher monthly payment, but far less total interest — shorter terms trade higher monthly cost for lower lifetime cost.
Frequently asked questions
No — this is the principal-and-interest payment only. Real mortgage bills often add property tax, insurance and sometimes HOA fees on top, so your actual monthly bill may be higher.
Interest is calculated on the remaining balance each month. Early on, the balance is at its highest, so interest takes the biggest bite; as principal gets paid down, more of each payment goes toward principal instead.