Total Interest Paid Over a Loan
Also known as cost of borrowing · lifetime interest
Units aren’t used in this calculation — every value is a plain number.
Worked example: 360 payments of $1,199.10 on $200,000 → $231,676 interest — press Try an example to run it live, then adjust anything.
Enter your known values, leave one input blank, and solves for the missing one. Tap a variable’s symbol to see what it means, with a typical value.
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Total Interest Paid Over a Loan explained
Multiply the payment by the number of payments, subtract what you borrowed, and what remains is the price of the money. The arithmetic is trivial and the answer is often shocking: 360 payments of $1,199.10 come to $431,676, so a $200,000 mortgage at 6% costs $231,676 in interest. You pay for the house more than twice, and the second time you get no house.
This is the number to look at when a lender offers a longer term to "lower your payment". Stretching a truck loan from 48 months to 72 does lower the monthly figure, but it raises the total handed over, because interest is charged on a balance that now falls more slowly. Read the payment and the total interest together, never one alone.
Total Interest Paid Over a Loan formula
- = Total interest paid ($)
- = Payment per period ($)
- = Number of payments
- = Principal borrowed ($)
Missing one of these? Work it out first, then come back
- Total interest paid — Currency Exchange Conversion, Gross Pay from an Hourly Wage
- Payment per period — Loan Payment (Amortized Loan or Mortgage), Present Value of an Annuity
- Number of payments — Loan Payment (Amortized Loan or Mortgage), Present Value of an Annuity
- Principal borrowed — Loan Payment (Amortized Loan or Mortgage), Currency Exchange Conversion