doubling time - the amount of time it takes for a given quantity to double in size or value at a constant growth rate
Population Doubling TimeFree Population Doubling Time Calculator - Determines population growth based on a doubling time.
Rule of 72Free Rule of 72 Calculator - Calculates how long it would take money to double (doubling time) using the rule of 72 interest approximation as well as showing the mathematical proof of the Rule of 72.