Free Math Calculators
45 free online math calculators covering arithmetic, percentages, fractions, averages, statistics, probability, algebra, geometry and number theory. Every tool explains the formula it uses and runs entirely in your browser — no signup, no ads, no data collection.
About math calculators
Mathematics underpins almost every other calculator on this site — a mortgage payment is an amortized formula, a BMI result is a ratio, a unit conversion is a multiplication. This section collects the pure-math tools that solve the problems people ask about most often: percentages, fractions, averages, statistics and basic algebra.
Each calculator has its own page with a clear formula explanation, a step-by-step worked example and guidance on how to interpret the result. If you want to understand the maths before you use the tool, start with a percentage guide, a guide to averages, or a standard deviation guide.
Arithmetic & Everyday Math
Everyday calculations — percentages, fractions, ratios and rounding.
Basic Calculator
Add, subtract, multiply and divide using a simple on-screen keypad.
Scientific Calculator
Trigonometry, logarithms, powers, roots and scientific notation.
Percentage Calculator
Find a percent of a number, what percent one value is of another, and more.
Percentage Change Calculator
Calculate the percentage increase or decrease between two values.
Percentage Difference Calculator
Compare two numbers and find the percentage difference between them.
Fraction Calculator
Add, subtract, multiply and divide fractions with results in lowest terms.
Decimal to Fraction Converter
Convert a decimal into its simplest fractional form.
Fraction to Decimal Converter
Convert any fraction into its decimal equivalent.
Mixed Number Calculator
Work with mixed numbers and improper fractions.
Ratio Calculator
Simplify ratios and solve for missing terms.
Proportion Calculator
Solve proportions of the form a : b = c : d.
Rounding Calculator
Round numbers to any decimal place, whole number or significant figure.
Absolute Value Calculator
Find the absolute value of any number or simple expression.
Random Number Generator
Generate random integers or decimals within any range.
Powers, Roots & Logarithms
Exponents, radicals and logarithmic functions.
Exponent Calculator
Raise numbers to any power, including negative and fractional exponents.
Square Root Calculator
Find the square root of any non-negative number, with simplification.
Cube Root Calculator
Calculate the cube root of any number, including negatives.
Logarithm Calculator
Compute logarithms to any base, including natural and base-10 logs.
Factorial Calculator
Calculate the factorial of any non-negative integer.
Scientific Notation Converter
Convert numbers between standard and scientific notation.
Significant Figures Calculator
Count significant figures and round values correctly.
Number Theory
Primes, divisors, sequences and number bases.
Prime Number Checker
Check whether a number is prime and list nearby primes.
Prime Factorization Calculator
Break a number into its prime factors and exponent form.
Greatest Common Factor Calculator
Find the GCF (GCD) of two or more integers.
Least Common Multiple Calculator
Find the LCM of two or more integers.
Number Sequence Calculator
Identify arithmetic and geometric sequences and their terms.
Binary Calculator
Perform arithmetic with binary numbers and see decimal results.
Hexadecimal Converter
Convert between decimal, binary, octal and hexadecimal.
Roman Numeral Converter
Convert between Roman numerals and decimal numbers.
Statistics & Data Analysis
Descriptive statistics, probability and distribution tools.
Average Calculator
Calculate the arithmetic mean of a list of numbers.
Weighted Average Calculator
Compute a weighted average from values and their weights.
Mean, Median, Mode & Range
Find the mean, median, mode and range of a dataset.
Standard Deviation Calculator
Compute sample and population standard deviation for a dataset.
Variance Calculator
Calculate sample and population variance from a list of values.
Probability Calculator
Compute probability for single events and independent events.
Permutation Calculator
Calculate permutations nPr for ordered selections.
Combination Calculator
Calculate combinations nCr for unordered selections.
Z-Score Calculator
Standardise a value and look up its position in a normal distribution.
Confidence Interval Calculator
Compute a confidence interval for a sample mean.
Algebra & Coordinate Geometry
Equations, lines, matrices and 2D geometry helpers.
Quadratic Formula Calculator
Solve ax² + bx + c = 0 including complex roots.
Linear Equation Calculator
Solve linear equations of the form ax + b = c.
Slope Calculator
Find slope, angle and line equation from two points.
Distance Formula Calculator
Calculate the distance between two points in a plane.
Midpoint Calculator
Find the midpoint between two coordinate points.
Matrix Calculator
Add, multiply, transpose and compute determinants of small matrices.
Math Guides
Short, plain-English explanations of the maths behind these tools.
How Percentages Work
Percent of a number, percentage change and percentage difference explained with examples.
Read guide MathHow to Calculate Averages
Mean, median, mode and weighted average — and how to pick the right one.
Read guide MathHow to Interpret Standard Deviation
What standard deviation actually measures and how to read the result in real-world terms.
Read guide MathHow to Calculate Percentage Increase
Percentage increase and decrease, plus percentage points versus percentages.
Read guideMath Calculator FAQs
The math section includes a basic calculator, scientific calculator, percentage tools, fractions, averages, statistics, probability, algebra helpers, number theory tools and base conversions. All 45 tools are listed on this page.
Yes. The basic calculator evaluates expressions using standard operator precedence — multiplication and division before addition and subtraction — with support for parentheses.
Yes. The standard deviation calculator supports sample (n−1) and population (n) variants so you can choose the one appropriate to your dataset.
Results use IEEE-754 double-precision floating-point arithmetic, which is accurate to about 15 significant decimal digits. Values displayed on screen are rounded for readability.
Yes. Every math calculator is free to use, requires no account and runs entirely in your browser. Your inputs are never transmitted to a server.
Explore Other Categories
Looking for something beyond pure maths? These sections may have what you need.
Geometry
Triangle solvers, circles, area, volume, plus construction estimators.
Finance
Mortgages, loans, savings, retirement and everyday money tools.
Unit Converters
Length, weight, temperature, volume, speed, data units and more.
Computing
Base conversion, subnetting, Base64, GPA and grade tools.