From percent to probability
Math
Percentages, fractions, statistics, geometry, and algebra — with step-by-step working.
Percentage Calculator
Solve any percentage problem: percent of, percent change, and more.
Fraction Calculator
Add, subtract, multiply, and divide fractions with simplified results.
Scientific Calculator
A full scientific calculator with trig, logs, and exponents.
Random Number Generator
Generate random numbers in any range, with or without repeats.
Standard Deviation Calculator
Compute standard deviation, variance, and mean for a data set.
Mean, Median, Mode Calculator
Find the mean, median, mode, and range of any data set.
Probability Calculator
Calculate probabilities of single and multiple events.
Permutation & Combination Calculator
Count arrangements and selections (nPr and nCr).
Z-Score Calculator
Convert values to z-scores and find probabilities under the normal curve.
Confidence Interval Calculator
Compute confidence intervals for a sample mean.
Exponent Calculator
Raise any base to any power, including fractional exponents.
Log Calculator
Evaluate logarithms with any base, including ln and log₁₀.
Root Calculator
Calculate square roots, cube roots, and nth roots.
Quadratic Formula Calculator
Solve quadratic equations with real or complex roots, step by step.
Slope Calculator
Find the slope and equation of a line through two points.
Ratio Calculator
Simplify ratios and solve proportions for missing values.
Rounding Calculator
Round numbers to any place value or significant figures.
Scientific Notation Calculator
Convert numbers to and from scientific notation and compute with them.
Greatest Common Factor Calculator
Find the GCF of two or more numbers with the work shown.
Least Common Multiple Calculator
Find the LCM of two or more numbers with the work shown.
Factor Calculator
List all factors and prime factorization of a number.
Binary Calculator
Convert and calculate between binary, decimal, and hex.
Hex Calculator
Convert and do arithmetic in hexadecimal.
Area Calculator
Find the area of rectangles, circles, triangles, and more.
Volume Calculator
Calculate the volume of common 3-D shapes.
Pythagorean Theorem Calculator
Solve for any side of a right triangle.
Circle Calculator
Find radius, diameter, circumference, and area from any one value.
Matrix Calculator
Add, multiply, and invert 2×2 matrices with determinants.
Percent Error Calculator
Measure how far an experimental value strays from the true value.
Weighted Average Calculator
Average values with different weights, like grades or portfolios.
Midpoint Calculator
Find the midpoint, distance, and slope between two points.
Distance Formula Calculator
Compute straight-line distance between points in 2D or 3D.
Triangle Calculator
Solve any triangle from three sides or two sides and the angle between.
Right Triangle Calculator
Solve a right triangle from one side and one acute angle.
Surface Area Calculator
Find surface area for boxes, cylinders, spheres, and cones.
Perimeter Calculator
Compute the perimeter of rectangles, triangles, and circles.
Arc Length Calculator
Get arc length, chord, and sector area from radius and angle.
Prime Number Checker
Test primality and find the neighboring primes of any number.
Fibonacci Calculator
Compute the nth Fibonacci number and the golden-ratio link.
Modulo Calculator
Find remainders with correct handling of negative numbers.
Decimal to Fraction Calculator
Convert any decimal into its simplest fraction form.
Long Division Calculator
Divide with quotient, remainder, and decimal result shown.
Exponential Growth Calculator
Project growth or decay at a constant percentage rate.
Half-Life Calculator
Find how much of a substance remains after any number of half-lives.
Interquartile Range Calculator
Compute quartiles, IQR, and outlier fences for a data set.
Correlation Calculator
Measure the Pearson correlation between two paired data sets.
Linear Regression Calculator
Fit the least-squares line through paired data with r².
Sample Size Calculator
Find the survey sample size for your margin of error.
Odds to Probability Calculator
Convert between odds and probability in both directions.
Dice Probability Calculator
Get the odds of any total when rolling two dice.
Binomial Probability Calculator
Probability of exactly or at least k successes in n trials.
Roman Numeral Converter
Convert numbers to and from Roman numerals up to 3,999.
Significant Figures Calculator
Count significant figures and round to any precision.