DEFINITION of 'Rule Of 70'
A way to estimate the number of years it takes for a certain variable to double. The rule of 70 states that in order to estimate the number of years for a variable to double, take the number 70 and divide it by the growth rate of the variable. This rule is commonly used with an annual compound interest rate to quickly determine how long it would take to double your money.
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BREAKING DOWN 'Rule Of 70'
Another useful application of the rule of 70 is in the area of estimating how long it would take a country's real GDP to double. Similar to compound interest rates, one can use the GDP growth rate in the divisor of the rule. For example, if the growth rate of the China is 10%, the rule of 70 predicts it would take 7 years (70/10) for China's real GDP to double.

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What does the rule of 70 indicate about a country's future economic growth?
The rule of 70 could be used to indicate the approximate number of years that it would take a company's economic growth to ... Read Full Answer >> 
How is the rule of 70 related to the growth rate of a variable?
The rule of 70 is related to the growth rate of a variable because it uses the growth rate in its approximation of the number ... Read Full Answer >> 
How can I use the rule of 70 to estimate a country's GDP growth?
You could use the rule of 70 to estimate a country's gross domestic product (GDP) growth by dividing 70 by the expected GDP ... Read Full Answer >> 
What is the difference between the rule of 70 and the rule of 72?
The rule of 70 and the rule of 72 give rough estimates of the number of years it would take for a certain variable to double. ... Read Full Answer >> 
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The most common types of regression an investor can use are linear regressions and multiple linear regressions. Regressions ... Read Full Answer >>