Learn what principal amount means in loans and investments, and how it affects your financial transactions. See a real-life example of a car loan and how to pay off the principal amount over time. You may calculate the simple interest on the principal amount on a daily, monthly, or yearly basis, and the calculator will display interest on the loan or the investment along witn the total amount payable. In the case of loans, the principal amount refers to the actual amount you borrowed from the lender and the remaining amount after you have repaid a part of it. Learn how to calculate the principal amount and interest on a loan with formulas and examples. Find out how to lower your interest burden and get a personal loan with Fibe at a nominal rate.