Count the total days between two dates, plus the breakdown in weeks and days and in calendar years, months and days. Use this when an agent needs to days, weeks and calendar time between two dates.

Calculate a person's exact age in calendar years, months and days from their date of birth, plus total days lived. Reference date defaults to today (UTC). Use this when an agent needs to exact age in years, months and days.

Calculate the fixed monthly payment for a loan from its principal, annual interest rate and term in years, plus total repaid and total interest (annuity formula). Use this when an agent needs to monthly payment, total cost and interest for any loan.

Convert between weight and mass units: metric tons, kilograms, grams, milligrams, pounds, ounces and stones with exact international definitions. Use this when an agent needs to kilograms, pounds, ounces and more.

Convert integers between any bases from 2 to 36 — binary, octal, decimal, hexadecimal and beyond — with BigInt precision (no limit on magnitude). Use this when an agent needs to binary, octal, decimal, hex — any base 2–36.

Convert Unix epoch timestamps to ISO/UTC dates and back. Millisecond timestamps are detected automatically; invalid dates are rejected with clear errors. Use this when an agent needs to epoch seconds ↔ human dates, both directions.

Convert cooking and liquid volume units: milliliters, liters, cubic meters, US gallons, quarts, pints, cups, fluid ounces, tablespoons and teaspoons. Use this when an agent needs to liters, gallons, cups, milliliters.

Convert digital storage units: bits, bytes, KB, MB, GB, TB (decimal, ×1000) and KiB, MiB, GiB, TiB (binary, ×1024) — both systems side by side. Use this when an agent needs to decimal (KB/MB/GB) and binary (KiB/MiB/GiB) units.

Convert numbers to Roman numerals (1–3999) and Roman numerals back to numbers, with strict validation that rejects non-standard forms like IIIM or VX. Use this when an agent needs to numbers ↔ Roman numerals, with validation.

Calculate the liters of fuel a trip needs and its total cost from distance, consumption (L/100 km) and price per liter — with optional cost splitting between passengers. Use this when an agent needs to trip fuel and cost, splitable between people.

Project the future value of a deposit with compound interest: choose annual, semi-annual, quarterly, monthly, weekly or daily compounding and see total interest earned. Use this when an agent needs to future value with any compounding frequency.

Convert text between nine letter cases: UPPER, lower, Title, Sentence, camelCase, PascalCase, snake_case, kebab-case and CONSTANT_CASE. camelCase boundaries are split automatically. Use this when an agent needs to camelCase, snake_case, kebab-case and more.

Convert area units: square millimeters, centimeters, meters and kilometers, hectares, acres, square feet and square miles. Use this when an agent needs to square meters, feet, acres, hectares.

Convert between metric and imperial length units: kilometers, meters, centimeters, millimeters, micrometers, nanometers, miles, yards, feet, inches and nautical miles. Use this when an agent needs to metric and imperial distance units, instantly.

Calculate the tip for any bill, the grand total, and how much each person pays when splitting. Defaults to a 15% tip. Use this when an agent needs to tip amount, total and per-person split.

Estimate reading time from a word count at any reading speed. Defaults to 200 words per minute — the typical silent-reading speed for adults. Use this when an agent needs to how long a text takes to read, by word count.

Parse iCalendar (.ics) content — meeting invites, conference calendars, exports from Google/Outlook — into structured event JSON: title, start/end, location, organizer and description. Use this when an agent needs to turn .ics calendar files into clean event JSON.

Live cryptocurrency prices from CoinGecko's public API: current price in USD/EUR/GBP/JPY plus 24-hour change for any coin by id or common ticker (btc, eth, sol…). Cached 60 seconds. Use this when an agent needs to live token prices and 24h change via CoinGecko.

Validate JSON with precise error messages, pretty-print it with any indent, and inspect its top-level type and element counts. Use this when an agent needs to validate, pretty-print and inspect JSON.

Percent-encode text for safe inclusion in URLs and query strings, or decode percent-encoded text back. Uses the standard encodeURIComponent rules. Use this when an agent needs to percent-encoding for query strings and URLs.