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Exponent Calculator

Enter a base and an exponent to compute base^exponent. Supports negative and fractional exponents. The relevant law of exponents is shown below the result.

Enter base and exponent

Try a negative exponent like -3, or a fractional one like 0.5 (which gives the square root).

Result

b^n--
Expression--
Enter values above to see the explanation.

How It's Calculated

An exponent tells you how many times to multiply the base by itself. A handful of rules cover every situation you will run into, from simple whole-number powers to negative and fractional ones that describe reciprocals and roots.

b^n = b x b x b ... (n times)
LawFormulaExample
Product ruleb^m * b^n = b^(m+n)2^3 * 2^4 = 2^7 = 128
Quotient ruleb^m / b^n = b^(m-n)3^5 / 3^2 = 3^3 = 27
Power of a power(b^m)^n = b^(m*n)(2^3)^2 = 2^6 = 64
Zero exponentb^0 = 1 (b not 0)7^0 = 1
Negative exponentb^(-n) = 1 / b^n2^(-3) = 1/8 = 0.125
Fractional exponentb^(1/n) = nth root of b8^(1/3) = 2
General fractionalb^(m/n) = (nth root of b)^m8^(2/3) = 4

Worked Example: 2^8

This is the default in the calculator. It uses repeated multiplication.

2^8 means multiply 2 by itself 8 times.
2^1 = 2
2^2 = 4
2^3 = 8
2^4 = 16
2^5 = 32
2^6 = 64
2^7 = 128
2^8 = 256

Worked Example: 4^(-0.5)

A negative fractional exponent combines two rules at once, which is where most confusion starts.

Step 1. The negative exponent means take the reciprocal: 4^(-0.5) = 1 / 4^0.5.
Step 2. The 0.5 exponent is the same as 1/2, which means square root: 4^0.5 = sqrt(4) = 2.
Result: 4^(-0.5) = 1 / 2 = 0.5

Common Mistakes to Avoid

A negative exponent is not a negative number; b^(-n) flips the base into a fraction but the result stays positive whenever b is positive. Another common mix-up is applying the exponent to a negative base incorrectly: (-2)^2 = 4, but -2^2 = -4, because without parentheses the exponent binds to 2 first and the minus sign is applied after. With fractional exponents, remember the denominator picks the root and the numerator picks the power, in that order, not the reverse.

For a rigorous treatment of exponent rules, see Wolfram MathWorld's exponent page and the Lamar University algebra notes on integer exponents.

Keep going with algebra

Exponents show up again the moment you start differentiating or integrating a polynomial.

Quick answers

Exponent Calculator FAQs

What is an exponent?

An exponent tells you how many times to multiply the base by itself. In b^n, b is the base and n is the exponent. For example, 2^4 = 2 x 2 x 2 x 2 = 16.

What does a negative exponent mean?

A negative exponent means take the reciprocal. b^(-n) = 1 / b^n. For example, 2^(-3) = 1 / 2^3 = 1/8 = 0.125.

What is a fractional exponent?

A fractional exponent represents a root. b^(1/n) is the nth root of b. So 8^(1/3) = the cube root of 8 = 2. More generally, b^(m/n) = the nth root of b raised to the m power.

What is anything to the power of zero?

Any nonzero number raised to the power of zero equals 1. This follows from the quotient rule: b^n / b^n = b^(n-n) = b^0, and any number divided by itself is 1.

What are the laws of exponents?

The main laws are: product rule (b^m * b^n = b^(m+n)), quotient rule (b^m / b^n = b^(m-n)), power of a power ((b^m)^n = b^(m*n)), negative exponent (b^(-n) = 1/b^n), and zero exponent (b^0 = 1).

Marcus Vance
About the author
Marcus Vance
Contributing Writer, Technology & Data, Encore Editorial

Marcus Vance spent a decade building data pipelines and testing calculation logic before he started writing about the math behind the tools. On MathCalcTools he checks every formula against the source math, then writes out the steps so a reader can follow the same path a calculator takes.