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Power of a Power Calculator

Simplify and calculate power of a power expressions (a^m)^n = a^(m*n) with step-by-step exponent multiplication, nested powers, and power tower comparison.

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The Power of a Power Property

In algebra, the power of a power rule states that when an exponential term is raised to another power, you multiply the exponents while keeping the base identical:

$$(b^m)^n = b^{m \cdot n}$$

Where $b$ is the base, $m$ is the inner exponent, and $n$ is the outer exponent. For example, $(2^3)^4$ means $(2^3)$ multiplied by itself 4 times: $(2 \times 2 \times 2) \times (2 \times 2 \times 2) \times (2 \times 2 \times 2) \times (2 \times 2 \times 2) = 2^{12} = 4,096$. Multiplying the exponents $3 \times 4 = 12$ gives the answer immediately.

Extending to Multiple Nested Exponents

The power of a power property holds for any number of nested exponents:

$$\left(\left(b^m\right)^n\right)^p = b^{m \cdot n \cdot p}$$

For instance, $((2^2)^3)^2 = 2^{2 \times 3 \times 2} = 2^{12} = 4,096$.

Negative and Fractional Exponents

The rule applies seamlessly when exponents are negative or fractional:

  • Negative exponents: $(3^{-2})^3 = 3^{(-2) \times 3} = 3^{-6} = \frac{1}{3^6} = \frac{1}{729}$.
  • Fractional exponents: $(4^{1/2})^3 = 4^{(1/2) \times 3} = 4^{3/2} = (\sqrt{4})^3 = 2^3 = 8$.

Power of a Power vs Power Towers (Order of Operations)

One of the most common pitfalls in algebra is confusing $(b^m)^n$ with $b^{m^n}$.

Parentheses force evaluation from inside out:

$$(2^3)^4 = 2^{3 \times 4} = 2^{12} = 4,096$$

Without parentheses, standard mathematical convention dictates that chained exponents evaluate from top to bottom (right to left):

$$2^{3^4} = 2^{(3^4)} = 2^{81} \approx 2.41785 \times 10^{24}$$

As you can see, $2^{12}$ and $2^{81}$ differ by 21 orders of magnitude! Always check whether grouping parentheses are present.

For other exponent laws, try the Multiplying Exponents Calculator, the Dividing Exponents Calculator, and the general Exponent Calculator.

Frequently Asked Questions

What is the rule for power of a power?

The power of a power rule states that $(a^m)^n = a^{m \cdot n}$. You multiply the exponents together and leave the base unchanged.

How is power of a power different from multiplying powers with the same base?

When multiplying powers with the same base, you add the exponents: $a^m \cdot a^n = a^{m+n}$. When raising a power to a power, you multiply the exponents: $(a^m)^n = a^{m \cdot n}$.

Does power of a power work if an exponent is zero?

Yes. For any non-zero base, $(b^m)^0 = b^{m \cdot 0} = b^0 = 1$. Similarly, $(b^0)^n = 1^n = 1$.

Why does $(2^3)^2$ equal 64 while $2^{3^2}$ equals 512?

With parentheses, $(2^3)^2 = 2^{3 \times 2} = 2^6 = 64$. Without parentheses, exponents have right-to-left associativity, so $2^{3^2} = 2^{(3^2)} = 2^9 = 512$.