Math & Statistics Tools

Averages, standard deviation, fractions, primes, bases and loans.

Average CalculatorMean, median, sum and range for a list of numbers.Median CalculatorThe middle value of an ordered list, outliers be damned.Standard Deviation CalculatorPopulation and sample standard deviation, clearly labelled.Fraction CalculatorExact fraction arithmetic with simplified results.Scientific CalculatorEvaluate expressions with a hand-written parser — no eval.Ratio CalculatorScale ratios: A:B with a new value for either side.GCD & LCM CalculatorGreatest common divisor and least common multiple.Number Base ConverterBinary, octal, decimal and hexadecimal, exactly.Prime Number CheckerPrimality test with full prime factorisation.Probability CalculatorCombinations, permutations and binomial probability.Loan CalculatorMonthly payment, total paid and interest for an amortising loan.Sales Tax CalculatorAdd tax to a net price or extract it from a gross price.Tip CalculatorTip amount, total and per-person share for a bill.

About these math tools

Exact arithmetic tools: BigInt fractions, hand-written expression parsing (no eval), trial-division factorisation and clearly-labelled population vs sample statistics.

Each tool is a small, focused utility with its own page, its own instructions and its own set of supported inputs. There is no account to create and no server-side processing step: the work happens on your device.