macalc — Everyday Calculator MCP Server

A curated core of 15 well-scoped calculator tools — income tax (France, US, UK, Canada), gross-to-net salary, mortgage, compound interest, loans, VAT, percentages, BMI, TDEE — with on-demand access to the full macalc catalog of 446 calculators (22 categories, 8 countries' tax systems) through a discovery + dispatcher workflow. Free, no API key required.

Core tools (default profile)

| Tool | What it does | |------|--------------| | calculate_french_income_tax | French income tax 2026 (Article 197 CGI, family quotient) | | calculate_french_salary | French gross → net salary 2026 (cadre / non-cadre / civil servant) | | calculate_us_federal_tax | US federal income tax 2026 (IRS brackets + standard deduction) | | calculate_uk_income_tax | UK income tax 2025/26 (HMRC bands, allowance taper) | | calculate_canada_federal_tax | Canadian federal income tax (CRA brackets + BPA) | | calculate_mortgage | Monthly payment, total interest, amortization schedule | | calculate_compound_interest | Lump-sum compound growth with yearly breakdown | | calculate_loan_payment | Generic amortizing loan (term in months) | | calculate_percentage | Percent of total / percent change / what-percent | | calculate_vat_generic | Add or remove VAT/GST/sales tax at any rate | | calculate_bmi | Body Mass Index + WHO category | | calculate_tdee | Maintenance calories from BMR + activity level | | list_bundles | Discover the 31 thematic bundles of the full catalog | | get_bundle_tools | List the tools inside one bundle | | call_any_calculator | Invoke any of the 446 hosted calculators by name |

Need something not in the core (notary fees, concrete volume, VMA, pet food…)? list_bundles → get_bundle_tools(bundle_id) → call_any_calculator(tool_name, arguments).

Prefer the raw 446-tool listing? Set the env var MACALC_MCP_FULL=1.

Quick Start

Two install modes — pick whichever your MCP client supports.

Option A — Remote (Streamable HTTP, zero install)

For clients with native remote MCP support (Claude Desktop ≥ 0.8, Cursor, Windsurf, VS Code MCP, etc.)

{
  "mcpServers": {
    "macalc": {
      "url": "https://macalculatriceenligne.com/api/mcp"
    }
  }
}

Option B — Local stdio proxy (works everywhere)

For clients that only speak stdio, or sandboxed environments:

{
  "mcpServers": {
    "macalc": {
      "command": "npx",
      "args": ["-y", "macalc-mcp"]
    }
  }
}

Or with Docker:

{
  "mcpServers": {
    "macalc": {
      "command": "docker",
      "args": ["run", "-i", "--rm", "ghcr.io/tresor4k/macalc-mcp:latest"]
    }
  }
}

That's it. No API key, no auth, no setup.

Note: Option A (remote URL) serves the full 446-tool catalog directly. Option B (this npm wrapper) serves the curated 15-tool core profile by default — lighter on your agent's context window — with the full catalog one dispatcher call away.

What's Inside — The Full Catalog

Finance (8 countries)

| Country | Tools | Examples | |---------|-------|---------| | 🇫🇷 France | 85+ | Income tax (IR 2026), salary gross→net, VAT, mortgage, notary fees, inheritance, retirement, unemployment, auto-entrepreneur | | 🇧🇪 Belgium | 35+ | Precompte professionnel, bonus emploi, pension, cheques repas, droits donation | | 🇨🇭 Switzerland | 30+ | Federal + cantonal tax, AVS/LPP, LAMal, 3rd pillar, frontalier | | 🇨🇦 Canada/Quebec | 25+ | Federal + provincial tax, RRQ, RQAP, REER, CELI, TPS/TVQ | | 🇺🇸 USA | 15+ | Federal income tax, FICA, state tax, 401k, HSA | | 🇬🇧 UK | 10+ | Income tax, NI, SDLT, student loan repayment | | 🇲🇦 Morocco | 10+ | IR, CNSS, TVA | | 🇸🇳 Senegal | 10+ | IR, CSS, TVA |

Health & Sport (50+ tools)

BMI, BMR (Mifflin/Harris-Benedict), TDEE, heart rate zones (Karvonen), 1RM (Epley/Brzycki), VMA (Cooper/Luc-Léger), VO2max, race prediction (Riegel), marathon/half pace, due date (3 methods), ovulation calendar, body fat (Navy method), daily calories, macros, hydration.

Math (60+ tools)

Percentages (increase/decrease/ratio), averages (weighted/geometric/harmonic), Pythagoras, area (triangle/circle/rectangle/trapezoid/polygon), volume (sphere/cylinder/cone/cube), perimeter, equations (1st/2nd degree), sequences (arithmetic/geometric), fractions, statistics (mean/median/mode/std dev), GCD/LCM, base conversion.

Construction (40+ tools)

Concrete volume & mix (B25 DTU 21), paint coverage, tile quantity, staircase dimensions (Blondel formula), insulation R-value, roof surface & slope, cable section (NF C 15-100), beam dimensioning (Eurocode 5), gravel/sand tonnage, wallpaper rolls, plasterboard sheets.

Science (25+ tools)

Ohm's law, Newton's laws, pH calculation, dilution (C1V1=C2V2), density, radioactive decay, speed of sound, ideal gas law, molar mass, concentration.

Conversions (40+ tools)

Temperature, distance, weight, volume, speed, pressure, energy, data storage, cooking units, shoe sizes, clothing sizes, currency.

Running & Cycling (35+ tools)

Pace calculator, VMA (6 test methods), VO2max, FTP, heart rate zones, race prediction, training plan, calorie burn, hydration needs, bike gear ratio, tire pressure.

Education (20+ tools)

GPA calculator (French bac/brevet system), weighted average, statistics, derivatives, combinatorics, probability distributions.

Real Estate (15+ tools)

Rental yield (gross/net/net-net), Pinel tax reduction, PTZ eligibility, DPE energy class, Carrez surface, notary fees by department, loan comparison.

Cooking & Nutrition (15+ tools)

Recipe nutrition calculator, baking conversions, glycemic load, caffeine intake, daily vitamins, unit conversions (cups/ml/oz).

Travel (10+ tools)

Luggage weight calculator, jet lag recovery, travel budget, voltage adapters, sun exposure time.

Animals (8+ tools)

Dog/cat food calculator, pet age converter (corrected formula), aquarium volume, breeding due date.

Astronomy (8+ tools)

Sunrise/sunset, moon phase, solar panel output, wind chill, heat index, carbon sequestration.

Textile (5+ tools)

Fabric yardage, knitting yarn calculator, ring/bra/hat size converters.

Technical Details

| Property | Value | |----------|-------| | Endpoint | https://macalculatriceenligne.com/api/mcp | | Transport | Streamable HTTP (stateless) | | Protocol | MCP v1 (@modelcontextprotocol/sdk ^1.27.1) | | Auth | None (free, no API key) | | Rate limit | 1,000 calls/day | | Response format | Structured JSON with formula, source, reference URL | | Discovery | https://macalculatriceenligne.com/.well-known/mcp/server.json |

Example Usage

Ask your AI assistant:

"Calculate the French income tax on 45,000€ for a single person"

The assistant calls calculate_french_income_tax with {income: 45000, parts: 1} and returns:

{
  "impot": 4611,
  "taux_effectif": "10.2%",
  "taux_marginal": "30%",
  "tranches": [
    {"min": 0, "max": 11624, "taux": "0%", "impot": 0},
    {"min": 11624, "max": 29638, "taux": "11%", "impot": 1982},
    {"min": 29638, "max": 45000, "taux": "30%", "impot": 2629}
  ],
  "source": "Article 197 CGI — Loi de finances 2026",
  "reference_url": "https://macalculatriceenligne.com/finance/fiscalite/calcul-impots/"
}

All Tool Categories

Finance FR (85)     Finance BE (35)     Finance CH (30)
Finance CA (25)     Finance US (15)     Finance UK (10)
Finance MA (10)     Finance SN (10)     Health (30)
Sport/Running (35)  Math (60)           Construction (40)
Science (25)        Conversions (40)    Education (20)
Real Estate (15)    Cooking (15)        Travel (10)
Animals (8)         Astronomy (8)       Textile (5)
Automotive (10)

Total: 446 tools (hosted catalog — counts per category are approximate)

Links

• Website: macalculatriceenligne.com
• MCP endpoint: macalculatriceenligne.com/api/mcp
• MCP info page: macalculatriceenligne.com/mcp/
• API docs: macalculatriceenligne.com/api-docs/
• Chrome extension: Calculer Partout
• Telegram bot: @macalculatrice_bot

License

MIT