CalcMate

Exponent Calculator

Enter a base and an exponent to get the power, written both as an ordinary number and in scientific notation, with the three same-base exponent laws worked through in your numbers.

Result82^3
Scientific notation8 × 10^0
Same base: x^a × x^b multiplying adds the exponents2^3 × 2^4 = 2^(3 + 4) = 2^7 = 128
Same base: x^a ÷ x^b dividing subtracts the exponents2^3 ÷ 2^4 = 2^(3 − 4) = 2^(-1) = 0.5
Power of a power: (x^a)^b multiplying the exponents(2^3)^4 = 2^(3 × 4) = 2^12 = 4096
Calculation2^3 = 2 × 2 × 2 = 8

A power is repeated multiplication, and a fractional exponent is a root: x^(1/n) is the n-th root of x.

Formula and calculation

Power xn=x multiplied by itself n timesx1/n=the n-th root of xx−n=1xnSame base xa×xb=xa+bxaxb=xa−b(xa)b=xa×b\begin{gathered}{\footnotesize\text{Power}}\ x^n = x\ \text{multiplied by itself}\ n\ \text{times} \quad x^{1/n} = \text{the } n\text{-th root of } x \quad x^{-n} = \dfrac{1}{x^n}\\ {\footnotesize\text{Same base}}\ x^a \times x^b = x^{a + b} \quad \dfrac{x^a}{x^b} = x^{a - b} \quad (x^a)^b = x^{a \times b}\end{gathered}
The standard exponent laws, as in any algebra textbook (Stewart, Precalculus). A fractional exponent p/q means the q-th root raised to the power p, so 8^(1/3) = 2 because 2 × 2 × 2 = 8. A negative base stays a real number only with a whole-number exponent.

Worked example

Eight to the power 1/3 is 2, the cube root, because 2 × 2 × 2 = 8. In scientific notation the same answer is 2 × 10^0. With the second exponent set to 2 the same-base laws work out as 8^(1/3) × 8^2 = 8^(1/3 + 2) = 8^2.333333 = 128.

Powers and roots are inverse operations

Raising to a power and taking a root undo each other: 2³ = 8 and the cube root of 8 is 2, which is why 8^(1/3) = 2. The square root calculator does the same job for any root, including odd roots of negative numbers such as the cube root of −8. Logarithms go one step further: a logarithm asks which exponent produces a number, so log10(1000) = 3 for the same reason that 10³ = 1000.

Why the same-base laws hold

x^a × x^b means a copies of x multiplied by b more, which is a + b copies in total, so the exponents add. Dividing cancels copies, which is why x^a ÷ x^b = x^(a − b) — and why x^a ÷ x^a = x^0 = 1 for any base. Raising a power to a further power repeats the whole product b times, giving a × b copies. Those three rules are the reason you rarely need to multiply a power out by hand, and they are worked through in your own numbers above the fold.

What the results mean

Result
The value of the base raised to the power you entered. A whole-number exponent is repeated multiplication (2^10 = 1,024), a fractional exponent is a root (8^(1/3) = 2) and a negative exponent is a reciprocal (2^(−3) = 0.125).
Scientific notation
The same answer in scientific notation, m × 10^e, with the mantissa m between 1 and 10 — the form used in science and engineering when a number is far from 1.
Same base: x^a × x^b
The product law worked through in your numbers: powers of the same base multiply by adding the exponents, x^a × x^b = x^(a + b).
Same base: x^a ÷ x^b
The quotient law in your numbers: powers of the same base divide by subtracting the exponents, x^a ÷ x^b = x^(a − b), so any power divided by itself is 1.
Power of a power: (x^a)^b
The power-of-a-power law in your numbers: an exponent raised to a further exponent multiplies them, (x^a)^b = x^(a × b).
Calculation
The calculation written out: the repeated multiplication behind a whole-number exponent, 1 ÷ x^n for a negative one, and the root behind a fraction such as 1/3.

Frequently asked questions

How do I work out 8 to the power of 1/3?

Type 8 as the base and 1/3 as the exponent and the answer is 2, because 2 × 2 × 2 = 8. A fractional exponent is a root: p/q means take the q-th root and then raise it to the power p. The square root calculator shows the same working for any root, square or not.

What does a negative exponent mean?

It means a reciprocal rather than a negative answer: 2^(−3) = 1 ÷ 2³ = 1 ÷ 8 = 0.125. Flipping the base under 1 is what a minus sign in the exponent does, which is why 10^(−2) is 0.01 and not −100.

Why is any number to the power of 0 equal to 1?

Because x^n ÷ x^n is 1, and the quotient law says it is x^(n − n) = x^0, so x^0 must be 1 for every non-zero base. The case 0^0 has no such argument and is a convention — this page follows the usual one and treats it as 1.

What is 2 to the power of 10?

1,024, which is why a kilobyte is 1,024 bytes. Doubling from 1 ten times gives 2, 4, 8, 16, 32, 64, 128, 256, 512, 1,024, and the calculator reports the same answer in scientific notation as 1.024 × 10^3.

Why does the calculator refuse a negative base with a fractional exponent?

Because the answer would not be a real number: (−8)^(1/2) is the square root of −8, which needs the imaginary unit i. Odd roots of negative numbers are real — the cube root of −8 is −2 — and the square root calculator handles those directly.