Glossary

Principal

The original amount of a loan or investment, before any interest is added.

1 min readReviewed Apr 1, 2026

Quick answer

Principal is the starting amount — the money you borrowed or invested before interest enters the picture.

Where you'll see it

On a mortgage statement, the principal is the part of the payment that actually pays down the balance — as opposed to interest, which just covers the cost of borrowing.

On a savings or investment account, principal is what you contributed, separate from earnings.