Numbers & Math

Calculators, converters and number theory.

107 tools

2D Transform Matrix Composer Compose translate / rotate / scale / skew into a single 3×3 matrix.
2D Vector Calculator Add, subtract, dot, normalize and angle-between two 2D vectors.
2×2 Matrix Calculator Determinant, inverse, product and eigenvalues of 2×2 matrices.
2×2 Matrix Eigenvalues Compute the eigenvalues of a 2×2 matrix (real or complex).
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3D Dot / Cross Product Compute dot and cross product of two 3D vectors.
3D Solid Geometry Calculator Compute the volume and surface area of spheres, cylinders, cones, cubes, boxes, pyramids and tori.
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3×3 Linear System Solver Solve Ax = b for a 3×3 system using Gauss-Jordan elimination.
A/B Test Significance Two-proportion z-test for A/B test conversions.
Age in Seconds Calculator Calculate age in seconds, minutes, hours, days and years.
APR ↔ APY Converter Convert nominal annual percentage rate to effective annual yield.
Aspect Ratio Calculator Calculate proportional width or height from any aspect ratio.
AWG Wire Table American Wire Gauge diameter, area, resistance and ampacity.
Bayesian Updater Update a prior probability with sensitivity and false-positive rate.
Big Number Calculator Arbitrary-precision integer and decimal calculator: add, sub, mul, div, mod, pow, gcd, lcm, factorial.
Binomial & Poisson Calculator PMF, CDF, mean and variance for binomial and Poisson distributions.
Bitwise Calculator Calculate AND, OR, XOR, NOT and shifts with binary and hexadecimal output.
Black-Scholes Option Pricer European option pricing with Greeks.
BMI / BMR Calculator Compute Body Mass Index and basal metabolic rate (Mifflin-St Jeor).
Boolean Expression Simplifier Reduce a Boolean expression with Quine-McCluskey.
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Chi-Square Test Chi-square goodness-of-fit between observed and expected counts.
Circle Calculator Derive diameter, circumference, area from radius — plus arc, sector and chord.
Cohen's d Effect Size Standardised mean difference (small/medium/large effect).
Collatz Sequence Generate the Collatz (3n+1) sequence, step count and peak value.
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Combinations & Permutations Calculator Compute nCr, nPr and related combinatorics values.
Combined Gas Law Solver Solve P₁V₁/T₁ = P₂V₂/T₂ for any one missing quantity.
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Complex Number Calculator Add, subtract, multiply, divide complex numbers.
Compound Interest Calculator Calculate final balance, interest earned and contributions over time.
Confidence Interval for the Mean Compute a normal-CI around the mean of a numeric sample.
Continued Fraction Expansion Expand any number into its continued fraction [a₀; a₁, a₂, …].
Convex Hull Builder Compute the 2D convex hull of a set of points (monotone chain).
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Cubic Equation Solver Solve ax³ + bx² + cx + d = 0 — three real or one real and two complex roots.
Decimal ↔ Fraction Convert a decimal to improper / mixed fraction and detect repeating decimals.
Discrete Fourier Transform Compute the DFT of a real signal — magnitude and phase for every frequency bin.
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Equation Plotter Plot any single-variable expression in x as an inline SVG with axes and zero crossings.
Expected Value Calculator Compute expected value, variance and standard deviation from outcomes and probabilities.
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Factorial / Big Integer Calculator Compute exact factorials and arbitrary-precision integer expressions.
Fibonacci Sequence Generator Generate Fibonacci numbers with index and comma-separated output.
Gamma & Beta Function Calculator Evaluate Γ(x) and B(a, b) for real arguments.
GCD / LCM Calculator Greatest common divisor and least common multiple of any list of integers.
Gray Code Converter Convert between binary and reflected Gray code in either direction.
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Half-Life / Radioactive Decay Calculator Project the amount remaining after exponential decay, plus decay constant and mean lifetime.
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Hamming(7,4) Code Encode 4 data bits into a Hamming(7,4) codeword, or decode 7 bits and fix a single-bit error.
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Ideal Gas Law Solver (PV = nRT) Solve PV = nRT for pressure, volume, moles or temperature.
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IEEE 754 Float Inspector Bit-level view of a number in FP16, BF16, FP32 or FP64.
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Inflation Calculator What is $X today worth in N years at i% inflation? (and vice versa)
Karnaugh Map Minimizer Minimize a Boolean function from minterms using a 2/3/4-variable K-map.
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Kinematics (SUVAT) Solver Solve the constant-acceleration SUVAT equations from any three of s, u, v, a, t.
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Line: Distance / Midpoint / Slope Given two points, get distance, midpoint, slope and line equation.
Linear Regression Ordinary least-squares slope, intercept and R² for any (x, y) list.
Loan / EMI Calculator Compute monthly payments, total interest and amortisation for a loan.
Logarithm Base Converter Convert log_a(x) into log_b(x) using change-of-base.
Magic Square Generator Generate magic squares for odd, doubly-even and singly-even orders.
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Mann–Whitney U Test Non-parametric two-sample rank test.
Markov Steady State Compute the steady-state probability vector of a row-stochastic matrix via power iteration.
Math Expression Evaluator Evaluate mathematical expressions with functions and constants.
Matrix Calculator Add, subtract and multiply 2x2 matrices, plus determinant values.
Modular Arithmetic Modular exponentiation, modular inverse, gcd, lcm.
Molarity Calculator Find solution molarity from moles (or mass + molar mass) and volume.
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Normal Distribution / Z-Score PDF, CDF, inverse CDF and Z-score for a normal distribution.
NPV / IRR Calculator Net present value and internal rate of return from a cash-flow stream.
Number Base Converter Convert between binary, octal, decimal and hexadecimal.
Numerical Integration Integrate f(x) over [a,b] with trapezoidal or Simpson's rule.
ODE Solver (Runge–Kutta 4) Numerically solve a first-order ODE dy/dx = f(x, y) with the classic RK4 method.
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Ohm's Law Calculator Solve V, I, R, P from any two known values.
Pascal's Triangle Generate Pascal's triangle for a chosen number of rows.
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Percentage Calculator Five percentage modes: of, is what %, % change, increase, decrease.
pH / pOH Calculator Convert between [H⁺], [OH⁻], pH and pOH for an aqueous solution.
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Photon Energy / Wavelength / Frequency Convert between a photon's wavelength, frequency and energy (λf = c, E = hf).
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Plane from 3 Points Find the plane equation Ax + By + Cz + D = 0 from three 3D points.
Polynomial Curve Fit Fit a polynomial to (x, y) data via least squares. Reports coefficients, R² and residuals.
Polynomial Interpolator Fit a polynomial through N points using Lagrange or Newton form.
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Polynomial Multiplier Multiply two polynomials given by coefficient lists.
Prime Number Checker & Factorizer Check primality, factorize and list primes up to N.
Projectile Motion Calculator Compute flight time, range, peak height and impact speed for a launched projectile.
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Proportion / Rule-of-Three Solver Solve a : b = c : x by cross-multiplication.
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PX REM EM Converter Convert CSS px, rem and em values with configurable base font size.
Pythagorean Triple Generator List primitive Pythagorean triples (a, b, c) with c ≤ N.
Quadratic Equation Solver Solve ax² + bx + c = 0 with real or complex roots.
Quaternion Calculator Quaternion arithmetic and axis-angle conversions.
Random Number Generator Generate cryptographically-random integers in a range.
Random Walk Simulator Simulate a 1-D random walk and report the path, final position and range.
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Regular Polygon Calculator Interior angle, perimeter, area, apothem of a regular n-gon.
Resistor Color Code Decode resistor color bands to resistance + tolerance.
Roman Numeral Converter Convert between Roman numerals and Arabic numbers.
Root Finder Find roots of f(x) = 0 using bisection or Newton's method.
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Salary Take-Home Calculator Estimate take-home pay after tax, social contributions and deductions.
Sample Size for a Proportion How many respondents do you need for a given margin of error?
Scientific Notation Converter Convert decimal numbers to and from scientific notation.
Set Operations Union, intersection, difference and symmetric difference of two newline lists.
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Sieve of Eratosthenes Visualizer Visualize the sieve of Eratosthenes up to N with crossed-out composites.
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Significant Figures Rounder Round a number to a chosen number of significant figures (decimal + scientific).
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Simple Pendulum Period Calculator Find a simple pendulum's period and frequency from its length (or vice-versa).
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Simplex LP (2 variables) Maximise an objective subject to ≤ constraints — 2-variable LP via vertex enumeration.
Snell's Law Refraction Calculator Compute the refraction angle and critical angle from refractive indices.
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Solution Dilution Calculator (C₁V₁ = C₂V₂) Solve the dilution equation C₁V₁ = C₂V₂ for any missing value.
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Statistics Calculator Mean, median, mode, standard deviation and more for any list of numbers.
Thin Lens Equation Calculator Solve 1/f = 1/do + 1/di and the magnification for a thin lens.
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Tip Calculator Calculate the tip and split a bill between any number of people.
Triangle Solver Solve a triangle from SSS, SAS or ASA inputs.
Truth Table Generator Boolean expression with A,B,C and &, |, !, ^, ->, <-> → truth table.
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Two's-Complement Bit-Width Viewer Inspect a number at any bit width with sign-extend toggle.
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Unit Converter Convert between length, mass, volume, area, speed, time and temperature.
VAT Calculator Add or remove VAT and see net, tax and gross amounts.
Venn Diagram Generator Generate a 2- or 3-set Venn diagram from element lists.
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Weighted Average & Percentile Calculator Compute mean, weighted mean, median, quartiles, percentiles and standard deviation from a list of numbers.
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Welch's t-Test Compare two samples' means with Welch's unequal-variance t-test.
π / e / φ Digits Viewer View the first hundreds of digits of π, e or the golden ratio φ.