Debt & Credit

Principal

The original amount of money borrowed in a loan or invested in an account, excluding interest.

Also known as: loan principal, principal balance, principal amount

What You Need to Know

Principal is the base amount you borrow or invest—the starting point before interest kicks in. Understanding principal is crucial for loans, mortgages, and investments.

Loan Context: When you borrow $300,000 for a mortgage, that's your principal. Your monthly payment covers both principal (paying down the loan) and interest (cost of borrowing). Early in a loan, most of your payment goes to interest. Over time, more goes toward principal.

Example Mortgage Payment:

  • Loan: $300,000 at 6% over 30 years
  • Monthly payment: $1,799
  • Month 1: $299 principal, $1,500 interest
  • Month 360: $1,790 principal, $9 interest

Investment Context: If you invest $10,000, that's your principal. Any gains from interest, dividends, or appreciation are separate. Protecting your principal while earning returns is the goal.

Extra Principal Payments: Making extra principal payments on a mortgage or loan dramatically reduces total interest paid. Even an extra $100/month can save tens of thousands and shave years off the loan.

Key Insight: The faster you pay down principal, the less interest you pay overall—because interest is calculated on the remaining principal balance.

Sources & References

This information is sourced from authoritative government and academic institutions:

Principal: The Amount You Actually Borrowed