Math utilities
Calculate fractions, percentages, powers, ratios, probability and statistics, convert Roman numerals, and use random, dice and grading utilities.
Random number generator
Generate bounded random integers with optional unique results using browser crypto.
Dice roller
Roll multiple dice with editable sides, individual results and a total.
Test grade calculator
Calculate a percentage and letter grade with editable thresholds and extra-credit rules.
GPA calculator
Calculate credit-weighted GPA from numeric course points on your chosen scale.
Fraction calculator
Convert decimals and mixed numbers to exact fractions and perform fraction arithmetic.
Factor calculator
Find prime factors, positive divisors, greatest common divisor and exact least common multiple.
Logarithm calculator
Calculate a real logarithm with an explicit positive base and argument.
Power and root calculator
Square numbers, raise powers and compute real nth roots with domain validation.
Percentage calculator
Calculate percent of a value, reverse percentages, change, difference and percentage tables.
Ratio and golden ratio calculator
Simplify and scale ratios or calculate golden-ratio segments and rectangle sides.
Probability and combinations calculator
Calculate equally likely probabilities, exact combinations and binomial event probability.
Roman numeral converter
Convert integers from 1 to 3999 to canonical Roman numerals and back.
Standard deviation calculator
Calculate sample or population standard deviation, variance, mean and median.
Sequence calculator
Test arithmetic or geometric sequences and calculate an nth term from supplied values.
Quadratic and completing-square calculator
Find real or complex roots, vertex, discriminant and completed-square form with a graph.
Linear equation grapher
Graph Ax+By=C, including vertical lines, with slope, intercepts and coordinate table.
Tape diagram equation builder
Build an equal-group tape diagram for nx+b=t and show the subtraction and division steps.
Scientific calculator
Evaluate arithmetic, powers, factorials, logarithms and trigonometry with explicit angle mode.
Image arithmetic calculator
Read a printed expression locally, review the recognized text and explicitly confirm arithmetic calculation.