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Simple Interest Rate Calculator

Enter the principal, maturity amount, and term in years to instantly back-solve the simple annual interest rate. See your earned interest and yield at a glance — ideal for checking the effective rate on deposits, loans, and bonds.

Input

$
$
yr

Result

Simple annual interest rate (term: 5 years)

1%

Principal

$1,000,000.00

Interest

$50,000.00

Maturity amount

$1,050,000.00

How it works

  • First find the interest: interest = maturity amount − principal, the difference between the total you finally receive and your original principal.
  • With simple interest, interest = principal × annual rate × years holds, so solving for the rate gives annual rate (%) = interest ÷ (principal × years) × 100.
  • Simple interest accrues only on the principal; unlike compound interest, the interest from each period is not added back to the principal. This tool assumes simple interest.
  • Enter the term in years. Fractional years such as 0.5 are supported, so you can also find rates for half-year holdings.
  • The annual rate is shown to six decimal places. Principal, interest, and maturity amount are displayed as rounded approximate values.
  • Note: the displayed rates and amounts are rough estimates. Actual yields on deposits, loans, and bonds may differ due to interest-payment methods, taxes, fees, and rounding.