# Calcgrid

> Open calculator engine for AI agents and people: finance, health, math, unit conversion, physics, chemistry, statistics and everyday calculators, each available as HTML, Markdown, JSON API, MCP tool and A2A skill.

184 calculators in 12 categories, each available as an HTML page, a Markdown document, a JSON API endpoint, an MCP tool and an A2A skill. No authentication.

## Entry points

- Documentation: https://tttkmbb.com/docs/index.md
- All calculators: https://tttkmbb.com/calculators.md
- API: https://tttkmbb.com/api/v1 · OpenAPI: https://tttkmbb.com/openapi.json
- MCP: https://tttkmbb.com/mcp · A2A: https://tttkmbb.com/a2a
- llms.txt: https://tttkmbb.com/llms.txt · ARD: https://tttkmbb.com/.well-known/ard.json · Agent Card: https://tttkmbb.com/.well-known/agent-card.json

## Categories

- [Finance](https://tttkmbb.com/finance.md) (20): Interest, loans, mortgages, savings, returns, taxes, discounts and business margins.
- [Health](https://tttkmbb.com/health.md) (16): Body metrics and nutrition: BMI, BMR, TDEE, body fat, ideal weight, macros, hydration, heart-rate zones, due date.
- [Sports & Fitness](https://tttkmbb.com/fitness.md) (8): Pace, race-time prediction, calories burned, one-rep max, VO2 max, steps and cycling.
- [Math](https://tttkmbb.com/math.md) (22): Percentages, algebra, number theory, sequences, fractions, exponents, logarithms and rounding.
- [Geometry](https://tttkmbb.com/geometry.md) (14): Area, perimeter, volume and surface area of 2D and 3D shapes; right-triangle solver.
- [Statistics & Probability](https://tttkmbb.com/statistics.md) (14): Descriptive statistics, z-scores, normal and binomial probability, confidence intervals, sample size, regression.
- [Unit Conversion](https://tttkmbb.com/conversion.md) (18): Length, mass, temperature, area, volume, speed, time, data, energy, pressure, power, angle, fuel economy and more.
- [Physics](https://tttkmbb.com/physics.md) (20): Kinematics, forces, energy, momentum, electricity, waves, gravitation, thermodynamics.
- [Chemistry](https://tttkmbb.com/chemistry.md) (10): Molar mass, moles, molarity, dilution, ideal gas law, pH, half-life, percent yield.
- [Everyday Life](https://tttkmbb.com/everyday.md) (20): Dates, ages, countdowns, trip fuel cost, electricity cost, tips, unit prices, grades, reading time, sleep.
- [Food & Cooking](https://tttkmbb.com/food.md) (9): Recipe scaling, cooking unit conversion, coffee ratio, calories from macros, dough and brine calculations.
- [Construction & Home](https://tttkmbb.com/construction.md) (13): Flooring, paint, concrete, tiles, roof pitch, stairs, gravel, drywall, fencing and decking estimates.