Not that I want to rain on anyone's parade, but at 2.50 %, it would take you roughly 29 years to double your money. At 1.50%, it would take roughly 48.
I always laugh when banks trumpet their interest rates. They've been so low for years that any little raise still results in bupkis.
What Is the Rule of 72?
The Rule of 72 is a quick, useful formula that is popularly used to estimate the number of years required to double the invested money at a given annual rate of return.
The Rule of 72 comes in handy for mental calculations to quickly gauge an approximate value. For this reason, the Rule of 72 is often taught to beginning investors as it is easy to comprehend and calculate. The Security and Exchange Commission also cites the Rule of 72 in grade-level financial literacy resources.
Years To Double: 72 / Expected Rate of Return
To calculate the time period an investment will double, divide the integer 72 by the expected rate of return. The formula relies on a single average rate over the life of the investment. The findings hold true for fractional results, as all decimals represent an additional portion of a year.