Exponent Calculator
Calculate exponents, powers, and roots. Raise any number to any power including negative and fractional exponents.
About the Exponent Calculator
An exponent calculator computes powers and roots of any number — including integer exponents, fractional exponents (roots), negative exponents (reciprocals), and decimal exponents. Exponents describe repeated multiplication and appear across mathematics, science, finance, and computing. Compound interest calculations use exponents (growth raised to the power of time). Scientific notation expresses very large and small numbers as powers of 10. Binary storage is powers of 2. Population growth and radioactive decay follow exponential functions. Our free exponent calculator handles base^exponent for any real base and exponent, displays results in both decimal and exact form where possible, shows the laws of exponents applied step by step, and converts between exponential and radical (root) notation. It also evaluates expressions combining multiple exponent operations with proper order of operations.
Formula
b^n = b x b x...n times | b^(-n) = 1/b^n | b^(1/n) = nth root of b | b^a x b^c = b^(a+c) | (b^a)^c = b^(ac)
How It Works
Basic: b^n = b multiplied by itself n times. 3^5 = 3 x 3 x 3 x 3 x 3 = 243. Zero exponent: b^0 = 1 for any non-zero b (because b^n / b^n = b^(n-n) = b^0 = 1). Negative exponent: b^(-n) = 1/b^n. 2^(-3) = 1/2^3 = 1/8 = 0.125. Fractional exponent: b^(1/n) = nth root of b. 8^(1/3) = cube root of 8 = 2. b^(m/n) = nth root of b^m = (nth root of b)^m. 8^(2/3) = (8^(1/3))^2 = 2^2 = 4. Key exponent rules: b^a x b^c = b^(a+c). (b^a)^c = b^(ac). (bc)^n = b^n x c^n. b^a / b^c = b^(a-c). Example: 2^3 x 2^4 = 2^7 = 128. (2^3)^2 = 2^6 = 64.
Tips & Best Practices
- ✓The Rule of 72: divide 72 by the annual growth rate to estimate the number of years to double. This works because of the mathematical properties of exponential growth: 2 = (1+r)^n, solving for n gives n = ln(2)/ln(1+r) ≈ 0.693/(r) ≈ 72/(100r).
- ✓Scientific notation: 3.5 x 10^6 = 3,500,000 (move decimal 6 places right for positive exponent). 3.5 x 10^(-4) = 0.00035 (move decimal 4 places left for negative exponent).
- ✓Comparing exponential bases: 2^10 = 1,024 ≈ 1,000. This approximation is essential in computer science: 2^10 kilobytes = 1 "kibi"-byte ≈ 1,000 bytes.
- ✓Compound interest exponential: $1,000 at 7% for 30 years = 1,000 x 1.07^30 = 1,000 x 7.612 = $7,612. The power here (1.07^30) is what makes compound interest so powerful over time.
- ✓Negative base with even versus odd exponent: (-2)^4 = 16 (positive result for even exponent). (-2)^3 = -8 (negative result for odd exponent). Even powers of negatives are always positive.
- ✓Order of operations with exponents: exponents are evaluated before multiplication and division. 2 x 3^2 = 2 x 9 = 18, NOT 6^2 = 36. Always evaluate exponents first unless parentheses specify otherwise.
- ✓Logarithms are the inverse of exponents: log_b(b^n) = n. The logarithm answers "what exponent do I need?" while the exponent calculator answers "what is the result of this power?"
- ✓Radioactive decay: A = A_0 x (1/2)^(t/half-life). Carbon-14 has a 5,730-year half-life. After 11,460 years (2 half-lives): remaining fraction = (1/2)^2 = 0.25 = 25% of original.
Who Uses This Calculator
Algebra and pre-calculus students evaluate expressions with integer, negative, and fractional exponents. Finance students model compound interest, exponential growth, and present value calculations. Computer science students work with powers of 2 for binary, hexadecimal, and storage calculations. Chemistry and physics students work with scientific notation and exponential decay. Biology students model population growth and disease spread exponential functions. Statistics students compute likelihood ratios and statistical power calculations involving exponents. Teachers create worked examples of exponent rules and applications.
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Frequently Asked Questions
What does an exponent mean?
An exponent tells you how many times to multiply a base by itself. 2⁵ = 2×2×2×2×2 = 32.