Find the interest earned and total amount from a principal, annual rate, and time using I = P x r x t.
Estimates only — not financial advice. Verify with your lender/advisor.
A simple interest calculator multiplies your principal by the annual rate and the number of years to find the interest, then adds it back to the principal for the total amount — interest is charged only on the original sum, never on interest already earned.
Simple interest uses the formula I = P x r x t, where P is the principal, r is the annual interest rate as a decimal (rate divided by 100), and t is the time in years. For example, $1,000 at 5% for 3 years earns $150 in interest. Results are estimates, not financial advice.
Simple interest is calculated only on the original principal, so the interest each period stays the same. Compound interest is calculated on the principal plus any interest already earned, so it grows faster over time. This calculator computes simple interest only.
Add the interest to the principal: Total = P + (P x r x t). The total amount is what you would repay on a simple-interest loan or receive back on a simple-interest investment at the end of the term.