Math Calculators
Fast, reliable math tools for everyday calculations — percentages, percentage change, fractions, averages, standard deviation, ratios, GCF / LCM, exponents, square roots, quadratics, scientific notation, permutations & combinations, probability, z-scores, prime factorization, logarithms and factorials. Every calculator is free, instant and private.
Percentage Calculator
Percent of, what percent, and percent change.
Fraction Calculator
Add, subtract, multiply or divide two fractions.
Average Calculator
Mean, median, mode, range, sum and count.
Standard Deviation
Sample and population standard deviation and variance.
Ratio Calculator
Simplify ratios and solve proportions A : B = C : D.
GCF & LCM
Greatest common factor and least common multiple of two or more numbers.
Exponent Calculator
Raise any base to any power — positive, negative, zero or fractional exponents.
Square Root Calculator
Find the square root of any number as a decimal and in simplified radical form, plus cube roots and other nth roots.
Quadratic Formula Calculator
Solve ax² + bx + c = 0 with the discriminant and real or complex roots.
Scientific Notation Converter
Convert decimals to scientific notation and back, with E-notation too.
Permutation & Combination
Calculate nPr (order matters) and nCr (order does not) from n and r.
Probability Calculator
Single-event probability plus AND, OR, neither and exactly-one for two independent events.
Z-Score Calculator
Standard score: how many standard deviations a value is from the mean, or back to a raw value.
Percentage Increase
Percent change between two values, or increase/decrease a value by a percent.
Prime Factorization
Prime factors of any number, written with exponents, plus a prime / composite check.
Logarithm Calculator
log, ln and any base — uses the change-of-base formula log_b(x) = ln(x) / ln(b).
Factorial Calculator
Exact n! for any whole number from 0 to 1000 using big-integer arithmetic.
Number Base Converter
Convert numbers between binary, octal, decimal, hexadecimal and any base from 2 to 36.
Slope Calculator
Slope, y-intercept, line equation, angle, distance and midpoint from two points.
Confidence Interval
z-based confidence interval for a mean at 90%, 95% or 99% confidence.
Significant Figures
Count significant figures in any number and round to a chosen number of sig figs.
P-value Calculator
Convert a z-score or t-score into a p-value for one- or two-tailed tests.
Sample Size Calculator
Find the survey sample size you need from confidence level, margin of error and population.
Percent Error Calculator
Compare a measured value to the accepted value to see percent error and absolute error.
Rounding Calculator
Round to decimal places or the nearest ten, hundred or thousand — half up, banker's, ceiling, floor or truncate.
Fraction to Decimal
Convert any fraction to its exact terminating or repeating decimal, with the repeating digits marked.