What method estimates how long it will take for an investment to double due to compound interest?

The Rule of 72 is a straightforward and widely-used method for estimating the time it takes for an investment to double in value due to compound interest. This rule states that you can divide the number 72 by the annual rate of return (expressed as a percentage) to approximate the number of years required for the investment to double.

For instance, if you have an investment that earns an annual return of 6%, you would calculate 72 divided by 6, which equals approximately 12 years for the investment to double. This method is particularly valuable because it provides a quick mental calculation without requiring complex formulas or calculations.

Other methods mentioned, like the Compound Interest Formula, though accurate, involve more complicated calculations that aren't as easily remembered or applied in casual scenarios. The Time Value of Money is a broader concept that includes various elements of finance but does not specifically provide a quick estimate for doubling investments, and the Exponential Growth Method refers to a mathematical representation of growth over time that doesn’t focus directly on the doubling time in the same intuitive way as the Rule of 72.