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Mathematics · Useful tools.
25 Mathematics tools. Compare options and choose a generator, converter or calculator for your task.
Mathematics
Work out proportions, percentages and everyday calculations. Use the expected units and review rounding before applying a result to a decision.
Percentage calculator
Calculate a percentage of a value, a percentage ratio or the percentage change between two numbers. Choose an operation and see the result.
Open toolRule of three
Solve direct or inverse proportions using the rule of three. Enter three values to find the fourth for the selected relationship.
Open toolPrime factorization
Decompose an integer into prime factors and see their exponents. Factor values from 2 up to one trillion in your browser.
Open toolLeast common multiple
Calculate the least common multiple, LCM, of two or more integers. Enter a list and get the exact result.
Open toolGreatest common divisor
Calculate the greatest common divisor, GCD, of two or more integers. Find the largest divisor shared by the values.
Open toolDivision remainder
Calculate the remainder of integer division without precision loss. Enter a dividend and a nonzero divisor.
Open toolRoman numeral converter
Convert numbers from 1 to 3999 to Roman numerals and convert Roman numerals back to decimal. Check canonical Roman notation.
Open toolRandom number generator
Generate integers in a range with or without repetition. Choose random, ascending or descending order and copy results created in your browser.
Open toolRandom draw
Draw random items from a list in your browser. Enter participants and the number of results to make a random selection.
Open toolArithmetic calculator
Add, subtract, multiply or divide two numbers. Select an arithmetic operation and copy the calculation result.
Open toolArea: rectangle
Calculate a rectangle's area by multiplying its base and height. Enter both lengths in the same unit to get the square area.
Open toolArea: square
Calculate a square's area from its side length. Check the side-squared formula and the result in square units.
Open toolArea: circle
Calculate a circle's area using πr². Enter the radius, not the diameter, and see the result in square units.
Open toolArea: parallelogram
Calculate a parallelogram's area from its base and perpendicular height. Use the same length unit to apply A = b × h.
Open toolArea: triangle
Calculate a triangle's area from its base and perpendicular height. The formula divides the product of these lengths by two.
Open toolArea: trapezoid
Calculate a trapezoid's area using its two parallel bases and height. Check the formula A = (B + b) × h / 2.
Open toolArea: rhombus
Calculate a rhombus's area from its two diagonals. Multiply the diagonal lengths and divide the product by two.
Open toolArea: sector
Calculate a circular sector's area from its radius and central angle in degrees. The tool accepts angles up to 360°.
Open toolArea: annulus
Calculate an annulus's area as the difference between two circles. Enter the outer and inner radii.
Open toolArea: ellipse
Calculate an ellipse's area with π × a × b. Enter both semi-axis lengths in the same unit rather than the diameters.
Open toolArea: pentagon
Calculate a regular pentagon's area from its side length. The calculation assumes five equal sides and equal interior angles.
Open toolArea: hexagon
Calculate a regular hexagon's area from its side length. Check the result of the formula 3√3 × side² / 2.
Open toolArea: polygon
Calculate a regular polygon's area from its side length and number of sides. For figures with equal sides and angles.
Open toolBrazilian CLT vacation calculator
Estimate gross Brazilian CLT vacation pay, including the one-third bonus and sold days. Enter pay and days; tax deductions are excluded.
Open toolBrazilian CLT termination calculator
Estimate gross Brazilian CLT termination amounts: salary, notice, vacation and 13th salary. Tax deductions and collective rules are excluded.
Open toolA toolbox for people who build.
Explore people and document generators, validators, text converters, calculators and development utilities. Each page explains how to use its tool and interpret the result. Generators create synthetic test data; validators check mathematical rules rather than replacing official record lookups.