3D Distance Calculator
Straight and grid distance between 3D points.
Math and Percent
Short everyday math: percent change, parts of a whole, and ratios.
Annulus Calculator
Ring area, outer circle, and width.
Arithmetic Sequence Calculator
Nth term, partial sum, and explicit rule from first term and difference.
Average Calculator
Mean, median, and range for any list of numbers with steps shown.
Catalan Numbers Calculator
Catalan number with formula and meaning.
Catenary Length Calculator
Catenary chain length and sag from curve parameter and support span.
Circle Calculator
Area, circumference, and diameter from radius.
Circle Segment Calculator
Circle segment area, arc, and chord.
Combination Calculator
nCr and nPr counts plus 1 in odds for any pick.
Complex Modulus Calculator
Modulus, argument, and conjugate of a+bi.
Cone Surface Area Calculator
Cone total surface, volume, and slant height.
Cone Volume Calculator
Volume, surface area, and slant height of a cone from radius and height.
Cube and Cuboid Calculator
Volume, surface, and diagonal of cubes and boxes.
Cube Root Calculator
Cube root with square and proof.
Cylinder Surface Area Calculator
Cylinder total surface, volume, and side area.
Distance and Midpoint Calculator
Distance, midpoint, and legs between two coordinate points.
E Series Calculator
Euler e approximation and error from terms.
Ellipse Area Calculator
Area of an ellipse from semi-major and semi-minor axes, both unit systems.
Ellipse Circumference Calculator
Ramanujan perimeter and area from semi axes.
Ellipsoid Volume Calculator
Volume from three semi axes with sphere match.
Expected Value Calculator
Mean outcome of a bet or forecast from values and probabilities.
Exponent Calculator
Powers and whole degree roots with inverse and rebuild checks shown.
Factorial Calculator
Exact n! with digit count and trailing zeros, 0 to 18.
Fibonacci Calculator
Exact Fibonacci numbers to F(70) with golden ratio drift.
Five Number Summary Calculator
Min, quartiles, median, max, IQR, and outliers for any list.
Fraction Calculator
Simplify fractions and convert to decimals, percents, and mixed numbers.
Frustum Volume Calculator
Bucket volume, side, and slant from radii.
GCF and LCM Calculator
Greatest common factor and least common multiple of two numbers.
Geometric Mean Calculator
Geometric mean of three positive values.
Geometric Sequence Calculator
Any term and partial sum of a geometric sequence from first term and ratio.
Golden Ratio Calculator
Golden split of any length with phi shown.
Harmonic Mean Calculator
True average of rates and ratios, beside the ordinary mean.
Helix Length Calculator
Coil wire length from radius, turns, and height.
Histogram Bin Calculator
Histogram bin counts by three rules.
IQR Outlier Calculator
IQR fences and flagged outliers from data.
Linear Interpolation Calculator
Interpolated value, slope, and fraction between two points.
Log Scale Doyle Calculator
Doyle board feet from log dimensions.
Logarithm Calculator
Base 10, natural, and base 2 logs for any positive value.
Long Division Calculator
Quotient, remainder, and decimal for any division.
Lucas Number Calculator
Lucas number with Fibonacci relation.
Map Scale Calculator
Real world distance in miles and km from map measurement and USGS map scale.
Margin of Error Calculator
Poll error band and interval from percent and sample size.
Matrix Determinant Calculator
Exact 2x2 and 3x3 determinants with invertibility verdict.
Matrix Inverse Calculator (2x2)
2x2 determinant and inverse entries.
Median Calculator
Median of any number list, with count, sorted middle, and mean.
Mode Average Calculator
Most frequent value, count, and shape.
Modulo Calculator
Remainder, quotient, and check for integer division A mod N.
Oblique Triangle Calculator
Oblique triangle solver for SAS, SSS, and ASA with angle sum check.
Pascal Triangle Calculator
Pascal row, C(n,k), and row sum.
Percentage Calculator
Solve the three everyday percent problems: what percent, percent of, and percent change.
Perfect Number Calculator
Perfect, abundant, or deficient with divisors.
Permutation Calculator
Ordered arrangements nPr beside combinations nCr for any n and r.
Pi Series Calculator
Leibniz pi approximation and error from terms.
Pixel Density Calculator
PPI sharpness band, megapixels, and pixel pitch from resolution and size.
Prime Number Checker
Prime or composite verdict, divisors, and next prime.
Pyramid Volume Calculator
Volume of a square pyramid from base side and height, in metric and imperial.
Pythagorean Theorem Calculator
Hypotenuse or missing leg for right triangles, with check.
Quadratic Equation Solver
Roots, discriminant, and vertex for any ax squared plus bx plus c.
Ratio Simplifier Calculator
Reduce ratios to simplest form with decimal and percent.
Regular Polygon Area Calculator
Area, perimeter, and angle of a regular polygon.
Rhombus Area Calculator
Rhombus area from diagonals, plus side and perimeter.
Right Triangle Calculator
Hypotenuse, angle, and ratios from two legs with SOHCAHTOA.
Roman Numerals Converter
Convert numbers to Roman numerals and Roman numerals back, 1 to 3999.
Root Mean Square Calculator
Sine RMS from peak volts, or RMS of any dataset.
Rounding Calculator
Round any value to chosen decimals with half up, down, or up modes and error.
Significant Figures Calculator
Count significant figures, scientific form, and rounding for any plain number.
Slope Calculator
Slope, intercept, and distance for a line through two points.
Sophie Germain Calculator
Sophie Germain test with safe pair.
Sphere Cap Volume Calculator
Dome volume, base, and curve from R and h.
Sphere Surface Area Calculator
Surface area of a sphere from radius, in metric and imperial.
Sphere Volume Calculator
Volume, surface area, and diameter of a sphere from radius, metric or imperial.
Square in a Circle Calculator
Largest square side and area in a circle.
Square Root Calculator
Principal square root of any non-negative number, with check and Newton steps.
Standard Deviation Calculator
Sample and population deviation, variance, and mean for number lists.
Summation Calculator
Sum, terms, and average for 1 through any n.
Torus Volume Calculator
Donut ring volume and surface from two radii.
Trapezoid Area Calculator
Area of a trapezoid from two bases and height, in metric and imperial.
Triangle Area Calculator
Area, perimeter, and type from three sides via Heron.
Triangle Centroid Calculator
Centroid, area, and perimeter from three corners.
Unit Circle Calculator
Sin, cos, tan from degrees on radius 1.
Vector Calculator
Magnitudes, dot product, and angle for two 2D vectors.
Washer Volume Calculator
Hollow washer area and volume from outer, inner radius, and height.
Weighted Average Calculator
Mean with per value weights plus plain mean for contrast.
Z-Score Calculator
Z-score, percentile rank, and plain reading from value, mean, and standard deviation.