 # Rule of 72 Calculator

## Enter Rule of 72 interest rate

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### How does the Rule of 72 Calculator work?

Free 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.
This calculator has 1 input.

### What 3 formulas are used for the Rule of 72 Calculator?

Doubling Money Time (t) = 0.72/i
(1 + i)t = 2

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### What 6 concepts are covered in the Rule of 72 Calculator?

approximation
anything that is intentionally similar but not exactly equal to something else.
compound interest
the interest you earn on principal and interest
A = (1 + r/n)nt
interest rate
the proportion of a loan that is charged as interest to the borrower or proportion of principal credit given to a depositor
logarithm
the exponent or power to which a base must be raised to yield a given number
rule of 72
a simplified formula that calculates how long it will take for an investment to double in value, based on its rate of return.
t ~ 72/i
yield
How much an investment returns in terms of interest rate