An exponent tells you how many times to multiply a base by itself. In 2^10, the base is 2 and the exponent is 10, so the result is 2 multiplied by itself ten times, which equals 1024. Exponentiation is repeated multiplication, just as multiplication is repeated addition.

What does a negative exponent mean?

A negative exponent is the reciprocal of the positive power. 2^-2 means 1 ÷ (2^2) = 1 ÷ 4 = 0.25. In general, x^-n equals 1 ÷ (x^n). Any non-zero number to a negative exponent is therefore a fraction between zero and the corresponding positive power.

What is a fractional exponent?

A fractional exponent is a root. x^(1/n) is the n-th root of x: 9^(1/2) is the square root of 9 (which is 3), and 8^(1/3) is the cube root of 8 (which is 2). More generally, x^(a/b) equals the b-th root of x raised to the power a. This is why the Root tab is just the inverse of the Power tab.

Why is 0 to the power 0 equal to 1?

By the IEEE 754 floating-point standard and the ECMAScript specification that JavaScript follows, 0^0 is defined as 1. This is the convention adopted by most calculators and programming languages because it keeps power series and combinatorial formulas consistent, even though the limit is mathematically indeterminate in some contexts.

What is the difference between a square root and a cube root?

A square root (degree 2) asks which number multiplied by itself gives the value: the square root of 9 is 3 because 3 × 3 = 9. A cube root (degree 3) asks which number multiplied by itself three times gives the value: the cube root of 27 is 3 because 3 × 3 × 3 = 27. The Root tab handles any degree n, not just 2 and 3.

Can you take the root of a negative number?

Only for odd-degree roots. The cube root of −8 is −2, because (−2) × (−2) × (−2) = −8. But there is no real square root of −4, because no real number multiplied by itself gives a negative result — that would require imaginary numbers. The calculator shows a dash whenever no real root exists, including any even or non-integer root of a negative number.

Exponent Calculator

Powers and roots in one widget. The formula shows alongside the answer.

Exponentiation is one of the most common operations in everyday math — compound interest, areas and volumes, scientific notation, and growth rates all lean on it. The two modes below cover both directions: raising a base to an exponent (a power) and the inverse operation of finding a root. Negative exponents, fractional exponents, and the real cube root of a negative number are all handled correctly. Every calculation runs in your browser and the formula is shown underneath so you can verify by hand.

Raise a base to an exponent

Base

Exponent

2 ^ 10

1024

2^10 = 1024

How to use

Pick the operation
Tabs across the top: "Power" raises a base to an exponent; "Root" finds the n-th root of a value. Pick the one that matches the question you have.
Fill in the two numbers
The result and the formula update as you type. There is no submit button.
Read the answer
The big tinted number is the answer. The mono-spaced line under it shows exactly how the answer was computed. A dash means there is no real result for those inputs.

Worked examples

Question	Inputs	Answer
2 to the power 10	2, 10	1024
2 to the power −2	2, −2	0.25
Square root of 9 (9 ^ 0.5)	9, 0.5	3
Cube root of 27	27, 3	3
Cube root of −8	−8, 3	−2
Square root of −4	−4, 2	—

Frequently asked questions

What is an exponent?: An exponent tells you how many times to multiply a base by itself. In 2^10, the base is 2 and the exponent is 10, so the result is 2 multiplied by itself ten times, which equals 1024. Exponentiation is repeated multiplication, just as multiplication is repeated addition.
What does a negative exponent mean?: A negative exponent is the reciprocal of the positive power. 2^-2 means 1 ÷ (2^2) = 1 ÷ 4 = 0.25. In general, x^-n equals 1 ÷ (x^n). Any non-zero number to a negative exponent is therefore a fraction between zero and the corresponding positive power.
What is a fractional exponent?: A fractional exponent is a root. x^(1/n) is the n-th root of x: 9^(1/2) is the square root of 9 (which is 3), and 8^(1/3) is the cube root of 8 (which is 2). More generally, x^(a/b) equals the b-th root of x raised to the power a. This is why the Root tab is just the inverse of the Power tab.
Why is 0 to the power 0 equal to 1?: By the IEEE 754 floating-point standard and the ECMAScript specification that JavaScript follows, 0^0 is defined as 1. This is the convention adopted by most calculators and programming languages because it keeps power series and combinatorial formulas consistent, even though the limit is mathematically indeterminate in some contexts.
What is the difference between a square root and a cube root?: A square root (degree 2) asks which number multiplied by itself gives the value: the square root of 9 is 3 because 3 × 3 = 9. A cube root (degree 3) asks which number multiplied by itself three times gives the value: the cube root of 27 is 3 because 3 × 3 × 3 = 27. The Root tab handles any degree n, not just 2 and 3.
Can you take the root of a negative number?: Only for odd-degree roots. The cube root of −8 is −2, because (−2) × (−2) × (−2) = −8. But there is no real square root of −4, because no real number multiplied by itself gives a negative result — that would require imaginary numbers. The calculator shows a dash whenever no real root exists, including any even or non-integer root of a negative number.

About

Why two modes?

A power and a root are inverse operations: a root is just a fractional power. Splitting them into separate tabs labels the question explicitly, so it is always clear which number is the base, which is the exponent, and which is the degree of the root.

Rounding behaviour

Results display with up to six decimal places, with trailing zeros trimmed. The raw IEEE 754 double is used for the underlying computation, so the displayed digits are exactly what JavaScript's ** operator would produce for the same operation.

When the answer is a dash

A dash means there is no real result for those inputs — for example a negative base with a fractional exponent, an even root of a negative number, or a root of degree zero. The calculator surfaces a dash rather than displaying NaN or Infinity.

Sources & references

Authoritative references behind the math, constants, and tables on this page. Verified by Buğra Sözeri on the dates shown and re-checked at every deploy.

ECMAScript Language Specification — Number::exponentiate — Defines the exact behaviour of JavaScript's ** operator, including 0^0 = 1 and NaN for negative bases with fractional exponents(as of 2026-06-27)
Math.pow() — MDN Web Docs — Reference for the exponentiation function and its documented edge cases(as of 2026-06-27)
Exponentiation — Wolfram MathWorld — Canonical mathematical reference for powers, roots, and the laws of exponents(as of 2026-06-27)