Use the formula: Interest Rate = (Interest ÷ Principal × Time) × 100

Identify the principal amount

Identify the interest earned or paid

Identify the time period in years

Divide interest by principal

Divide the result by time

Multiply by 100 to get the percentage

For simple interest, use: I = P × R × T

Rearrange to find rate: R = I ÷ (P × T)

For annual rate, ensure time is in years

For monthly rate, divide the annual rate by 12

For daily rate, divide the annual rate by 365

Check whether the rate is nominal or effective

Use the loan or investment statement if the rate is already given

Verify all units match before calculating