Exponent and Root Calculator

Raise a number to any power or take any root, including negative and fractional exponents.

  • Reviewed October 2026
  • Formula and worked example below
  • Free, no sign-up, runs in your browser
Enter your numbers to see the result.

Exponents

An exponent says how many times to multiply a number by itself: 2¹⁰ = 2 × 2 × … × 2 (ten times) = 1,024.

Exponent rules

RuleExample
xᵃ × xᵇ = xᵃ⁺ᵇ2³ × 2⁴ = 2⁷ = 128
xᵃ ÷ xᵇ = xᵃ⁻ᵇ5⁶ ÷ 5⁴ = 5² = 25
(xᵃ)ᵇ = xᵃᵇ(3²)³ = 3⁶ = 729
x⁰ = 17⁰ = 1
x⁻ⁿ = 1 ÷ xⁿ2⁻³ = 1/8 = 0.125
x^(1/n) = ⁿ√x27^(1/3) = 3

Roots

A root reverses an exponent. The cube root of 27 is 3 because 3³ = 27. Even roots (square root, fourth root) of negative numbers are not real numbers, while odd roots of negative numbers are: the cube root of −8 is −2.

Where exponents appear

  • Compound interest: money grows by (1 + r)ⁿ.
  • Computing: storage sizes are powers of 2, such as 2¹⁰ = 1,024.
  • Science: scientific notation uses powers of 10.
  • Area and volume: squaring and cubing lengths.

Frequently asked questions

What is any number to the power of 0?

Any non-zero number raised to the power 0 equals 1. 0⁰ is usually defined as 1 in algebra but is treated as undefined in some contexts.

What does a negative exponent mean?

It means the reciprocal: x⁻ⁿ = 1 ÷ xⁿ. For example, 10⁻² = 0.01.

How do I calculate a fractional exponent?

x^(a/b) is the b-th root of x raised to the power a. For example, 8^(2/3) = (cube root of 8)² = 4.

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Last reviewed Oct 20, 2026. Results are estimates; check important decisions with a qualified professional.