10 subcategories · 130 calculators
Math
The Math section covers arithmetic, percentages, fractions, algebra, geometry, statistics, and linear algebra. Tools range from everyday percentage and proportion calculators to geometry tools for areas, volumes, and triangle problems, through to GPA and grade calculators for students. Every calculator shows the formula it uses alongside the result, so the answer is always accompanied by an explanation of how it was reached.
Subcategories
Arithmetic
Percentage, ratio, average, and everyday arithmetic tools.
Number Systems
Fraction, decimal, and number representation conversion tools.
Number Theory
GCF, LCM, prime factorisation, factorial, and sequence calculators.
Algebra
Powers, logarithms, slope, and equation tools.
Calculus
Derivative, integral, limit, and series calculators.
Geometry
Shape, area, volume, and theorem calculators.
Statistics
Standard deviation, mean, median, confidence intervals, and descriptive statistics tools.
Probability
Combinations, permutations, dice probability, and Bayesian calculators.
Linear Algebra
Matrix determinant, inverse, and matrix-operation calculators.
General
Scientific calculator and general-purpose math tools.
Popular tools
Math / Algebra / Functions
Absolute Value Calculator
Evaluate a real number, fraction, decimal, or expression, then see the simplified value before absolute value, the non-negative result, number-line distance.
Math / Linear Algebra
Angle Between Vectors Calculator
Use the angle between vectors calculator to find the smallest angle between two 2D or 3D vectors with step-by-step dot-product working, cosine similarity.
Math / Statistics
ANOVA Calculator
Compare three or more independent groups with a one-way ANOVA calculator that returns the F statistic, p-value, ANOVA table, group means, effect sizes.
Math / Algebra / Functions
Antilog Calculator
Use an antilog calculator to turn log values back into original numbers for base 10, e, 2, or any custom base, with worked scenarios, inverse checks.
Math / Geometry / General
Area Calculator
Use this area calculator to find the area of common shapes, convert between square feet, square metres, acres, and hectares.
Math / Geometry / Solid Shapes
Barrel Volume Calculator
Calculate barrel, cask, or drum volume in litres and US or UK gallons from bilge diameter, head diameter, and height.
Common questions
Math questions.
Which calculator should I use for percentage questions?
Use the percentage calculator for general questions like "what is X% of Y" or "X is what percent of Y". Use the percentage increase or decrease calculators when you need to find the new value after a rate change, or work out the percentage change between two numbers. The proportion calculator is best when you are solving ratios or scaling values in a:b = c:d form.
What is the difference between the grade calculator and the GPA calculator?
The grade calculator tracks weighted coursework within a single class — it estimates your running average and the score needed on remaining work to reach a target final grade. The GPA calculator works across multiple classes: it converts letter grades or percentage scores into grade points and computes a weighted GPA for a semester or cumulative record.
Do the geometry calculators cover 3D shapes as well as 2D?
Yes. The geometry section includes both 2D tools (area of triangles, circles, rectangles, and polygons) and 3D tools (volume and surface area of spheres, cylinders, cones, and rectangular prisms). Each tool shows the standard formula and breaks down the calculation step by step.