Math & finance
Safe expression calculator, statistics, unit conversion across 13 categories (length, mass, temperature, …) via POST /api/unit-convert, percentage/number formatting, CIDR subnets, compound interest and loan math.
Calculator
POST /api/calcSafely evaluate an arithmetic expression (+ - * / % ^ and parentheses). No code execution - a real parser, not eval.
Statistics
POST /api/statsDescriptive statistics for an array of numbers: count, sum, mean, median, mode, min, max, range, variance, stddev, and p…
Unit convert
POST /api/unit-convertConvert a value between units of length, mass, temperature, volume, area, speed, time, data, pressure, energy, power, an…
Percentage
POST /api/percentagePercentage helper. op: "of" (a% of b), "change" (% change a→b), "ratio" (a is what % of b).
Number format
POST /api/number-formatFormat a number: thousands separators, fixed decimals, optional currency, or compact (1.2K / 3.4M).
CIDR calculator
POST /api/cidrParse an IPv4 CIDR block: network address, broadcast, first/last host, netmask, and host count. Optionally test if an IP…
Finance
POST /api/financeFinancial math. op: "compound" (future value of principal at a rate) or "loan" (monthly payment + total for a loan).
Geo distance (haversine)
POST /api/geo-distanceGreat-circle distance between two latitude/longitude points using the haversine formula. Returns kilometers and miles. D…
Prime factorize
POST /api/prime-factorizeFind the prime factorization of an integer via trial division. Returns the list of prime factors (with repeats), a human…
GCD & LCM
POST /api/gcd-lcmCompute the greatest common divisor (Euclidean algorithm) and least common multiple of two positive integers. Also repor…
Combinatorics
POST /api/combinatoricsCompute combinations C(n, r) or permutations P(n, r) using BigInt for exact arbitrary-precision results. Returns the res…
Matrix multiply
POST /api/matrix-multiplyStandard matrix multiplication of two 2D arrays: A[m×k] × B[k×n] → C[m×n]. Validates that inner dimensions match. Each d…
Modular arithmetic
POST /api/mod-arithmeticModular arithmetic operations: mod (a mod m), modpow (a^b mod m via fast exponentiation), and modinverse (a^-1 mod m via…