Ok, what if our interest isn’t 100% What if it’s 5% or 10%? Simple. As long as rate × time = .693, we’ll double our money: rate · time = .693 time = .693/rate So, if we only had 10% growth, it’d take .693 / 10% or 6.93 years to double. To simplify things, let’s multiply by 100 so we can talk about 10 rather than .10: time to double = 69.3/rate, where rate is assumed to be in percent. Now the time to double at 5% growth is 69.3/5 or 13.86 years. However, 69.3 isn’t the most divisible number. Let’s pick a close neighbor,
