Percentages, ratios, and everyday arithmetic.
From quick percentage calculations to statistics and algebra, this category covers the everyday math problems people actually search for - splitting a bill, checking a grade, or working out a ratio - without wading through a full scientific calculator's worth of unrelated functions.
Find what X percent of a number is, in one step.
Calculate percentage increase or decrease between two values.
Calculate the mean, median, and sum of a list of numbers.
Add, subtract, multiply, or divide two fractions.
Show pi (π) to a chosen number of decimal digits, up to 100.
Divide two whole numbers and see the full step-by-step long division work.
Multiply two whole numbers and see the full step-by-step long multiplication work.
Find the greatest common divisor and least common multiple of two numbers.
Find all factors and the prime factorization of a whole number.
Calculate the standard deviation and variance of a list of numbers.
Calculate the t-statistic for a two-sample independent t-test.
Calculate Cohen's d to measure the standardized difference between two group means.
Calculate the Mann-Whitney U statistic for two independent groups, a non-parametric alternative to the t-test.
Calculate the nth term and sum of an arithmetic or geometric sequence.
Calculate the expected number of draws needed to collect all n distinct items.
Calculate the area and volume ratio between two similar figures from their side length ratio.
Calculate the Pearson correlation coefficient (r) between two paired sets of numbers.
Calculate a z-score (standardized score) and percentile from a value, mean, and standard deviation.
Calculate precision, recall, F1, specificity, accuracy, and other diagnostic test metrics from a confusion…
Convert between probability and odds, in either direction.
Calculate the probability that a normally distributed value falls between two values, given the mean and…
Calculate the odds of winning a lottery jackpot from the pool size and how many numbers are drawn.
See the exact probability and odds of every 5-card poker hand ranking, out of a standard 52-card deck.
Calculate the square root, square, and cube root of a number.
Simplify a ratio to its lowest terms.
Calculate a photo or video's aspect ratio, and find a matching height or width for a new size.
Calculate a base raised to a power.
Calculate the logarithm of a number in any base, including natural log and log base 10.
Calculate dot product, cross product, magnitude, and angle between two 3D vectors.
Calculate the great-circle distance and compass bearing between two GPS coordinates.
Solve ax² + bx + c = 0 for x using the quadratic formula.
Also works as a formula for the volume of a cone lookup - calculate the volume, surface area, and slant…
Also works as a formula for the volume of a cylinder lookup - calculate the volume and surface area of a…
Calculate the hypotenuse (or a missing leg) of a right triangle using the Pythagorean theorem.
Calculate the distance between two points on a coordinate plane.
Calculate all three angles and the area of a triangle from its three side lengths.
Calculate the probability of drawing exactly k successes from a population without replacement.
Calculate the area and perimeter of a trapezoid.
Calculate the volume and surface area of a rectangular prism (box) from its length, width, and height.
Calculate the slope between two points, plus the line's equation and angle.
Calculate the arc length and area of a circle sector (pie-slice) from radius and angle.
Calculate slope grade as a percentage, angle, and ratio from rise and run - for roads, ramps, and roofs.
Calculate the molecular weight (molar mass) of a chemical formula, like H2O or C6H12O6.
Calculate a compound's empirical formula from the mass percentage of each element.
Solve a system of two linear equations (ax + by = e, cx + dy = f) for x and y.
Solve a linear equation of the form ax + b = c for x.
Calculate the eigenvalues and eigenvectors of a 2x2 matrix.
Solve a linear inequality of the form ax + b [<, >, ≤, ≥] c for x.
Balance a chemical equation by finding the correct whole-number coefficients.
Calculate the solubility product constant (Ksp) from molar solubility and ion stoichiometry.
Calculate the pH at any point during a strong acid / strong base titration.
Find which of two reactants is the limiting reagent from their mass, formula, and stoichiometric coefficient.
Calculate half-life, remaining amount, or elapsed time for first-order decay (radioactive decay or…
Calculate genotype and allele frequencies using the Hardy-Weinberg equilibrium equation.
Calculate a test or exam grade as a percentage and letter grade from points earned and total points.
Calculate an overall course grade from category scores and weights, like homework, tests, and a final exam.
Calculate your GPA on a 4.0 scale from letter grades and credit hours across up to 5 courses.
Solve for speed, distance, or time using speed = distance / time - enter any two to find the third.
Calculate the flight time, maximum height, and range of a projectile launched at an angle.
Calculate final velocities for an elastic or perfectly inelastic collision between two objects.
Calculate voltage, current, resistance, or power - enter any two to find the other two.
Solve a right triangle's missing sides, angles, and area from any two known sides.
Calculate absolute risk reduction (ARR), relative risk reduction (RRR), and number needed to treat (NNT) from…
Calculate the survey or study sample size needed for a chosen confidence level and margin of error.
Calculate a confidence interval for a sample mean.
Calculate the mean, median, mode, and range of a data set.
Convert between numbers and Roman numerals, in either direction.
Calculate astronomical distance from apparent and absolute magnitude, or vice versa.
Compare the energy released by two earthquake magnitudes.
Calculate pressure altitude from field elevation and altimeter setting.
Calculate a circle's radius, diameter, circumference, and area from any one known value.
Convert a repeating decimal into an exact fraction, with steps.
Calculate nPr (permutations) and nCr (combinations) for a set of n items chosen r at a time.
Plot the graph of a function y = f(x) online, with zoom and pan controls.
A free online scientific calculator with trig functions, logs, powers, and roots, with a degree/radian toggle.
Round a number to N significant figures, count the significant figures in a number, or convert it to…