Scientific unit conversion for pressure, energy, and molarity using exact conversion factors.
Periodic table element lookup by symbol or atomic number, returning name, atomic mass, and category. Covers the most commonly referenced elements.
Lookup of standard physical constants (speed of light, gravitational constant, Planck constant, elementary charge, Avogadro number, Boltzmann constant, gas constant, ele…
Descriptive statistics summary (mean, median, variance, standard deviation, and 25th/75th/90th percentiles via linear interpolation, matching R and numpy's default "type…
Prime factorization of an integer via trial division, returning the full list of prime factors (with repetition).
Solves a system of linear equations (Ax = b) using the ml-matrix library's LU decomposition (LuDecomposition), with a near-singularity guard beyond the library's exact-s…
Matrix operations: multiply, transpose, determinant, and invert, for matrices up to 20x20. Uses the ml-matrix library's LU decomposition (LuDecomposition) for determinan…
Arbitrary-precision integer arithmetic (add, subtract, multiply, power) beyond IEEE-754 float precision, using native BigInt. Operands are passed as digit strings so pre…
Alcohol spending and opportunity-cost calculator. Sums home and going-out drinking costs plus associated rideshare costs into monthly and yearly totals, then projects wh…
Keeping up with inflation calculator. Computes the pre-tax raise needed under two scenarios — keeping the same dollar amount saved, or maintaining the same savings rate…
Emergency fund calculator. Multiplies monthly essential expenses by a chosen runway length (in months) to compute a target emergency savings amount.
Savings rate calculator. Divides the gap between monthly take-home income and spending by income to produce your personal savings rate as a percentage.
Portfolio rebalancing calculator. Given current holdings and target allocation percentages, computes the dollar gap per asset and the monthly buy/sell inflow needed to r…
Rental property investment calculator. Full multi-year deal analysis for a rental property deal: mortgage, per-category rent/expense growth, a sale scenario, IRR, and cu…
Cash-on-cash return calculator for real estate investing. Runs a full multi-year deal analysis (per-category rent/expense growth, a sale scenario, IRR) and headlines the…
Compound interest calculator. Projects the ending value of an investment given a starting principal, monthly contributions, and an annual interest rate, compounded month…
Purchase impact on FIRE timeline calculator. Runs the FIRE net-worth simulation twice — with and without a one-time purchase amount deducted at a given year — and report…
Windfall impact on FIRE timeline calculator. Runs the FIRE net-worth simulation twice — with and without a one-time lump sum added at a given year — and reports how many…
Barista FIRE calculator. Simulates net worth growth through a full-time-saving phase and then a reduced-target phase funded partly by part-time/side income after quittin…
Fat FIRE calculator. Same year-by-year compound-growth simulation as the standard FIRE calculator, framed for a higher, more lifestyle-preserving retirement spending tar…
Coast FIRE calculator. Computes the lump sum needed today, invested with zero further contributions, to grow into your full retirement number by your target retirement a…
Buy 1,000 csno chips for $0.10. csno is a provably-fair arcade for AI agents: coinflip, dice and European roulette, settled in USDC over x402. Buy chips once, then play…
Execute HTTPS requests reliably with automatic retries for rate limits, temporary server failures, network errors and timeouts. One $0.02 USDC payment creates one durabl…
Validate an email address: syntax, live MX record check, and disposable-domain detection.
