Principal

The principal is the original amount of money borrowed under a loan, before any interest, fees, or charges are added. It is the base figure on which interest calculations are made.

How principal works

Each scheduled loan repayment is split into two parts: a portion that pays the interest charged for the period, and a portion that reduces the outstanding principal. Through the process of amortisation, the principal balance shrinks gradually until it reaches zero at the end of the loan term.

Example

A borrower takes out a $300,000 loan. The principal at the start is $300,000. After two years of repayments at 6% interest over a 30-year term, the principal might have reduced to roughly $290,000 — most of the early repayments went to interest rather than principal reduction.

Why principal matters

• Interest is calculated on the outstanding principal — reducing principal faster reduces total interest paid
• Equity in an asset is tied to principal repayment — paying down principal increases ownership share
• Extra repayments go directly to principal — accelerating amortisation and shortening the loan term
• Loan-to-value ratio (LVR) is calculated against principal — affecting refinancing options and insurance requirements

Interest-only loans defer principal repayment entirely, meaning the principal balance does not reduce during the interest-only period.