calculox MCP Server

Connect calculox to Claude, ChatGPT, or any MCP-compatible AI assistant — same verified formulas as the website, callable directly from your conversation.

What's exposed

  • 14 calculator tools — EMI, SIP, income tax, FD, RD, GST, CAGR, simple interest, percentage, profit margin, retirement corpus, home loan vs rent, BMI, and a scientific expression evaluator. Each one calls the exact same calculation engine as the matching page on this site, so the numbers always match.
  • 4 visual widgets — the EMI, SIP, BMI, and income tax tools also expose an MCP Apps interactive UI — the same calculator page, embedded inline in a supporting host, pre-filled with the numbers the tool just computed. Host support for this is still rolling out; if your client doesn't render it yet, the tool still returns a plain text/JSON result.
  • 24 blog guidesas reference resources — calculox's own explainer articles (how EMI is calculated, old vs new tax regime, SIP vs lump sum, etc.), available for a model to read as grounding context.

Server URL

https://www.calculox.in/api/mcp

Streamable HTTP, unauthenticated (these are free public calculators, no account or API key needed).

Connect your client

Claude Desktop

Add to your claude_desktop_config.json (Settings → Developer → Edit Config), then restart Claude Desktop.

{
  "mcpServers": {
    "calculox": {
      "url": "https://www.calculox.in/api/mcp"
    }
  }
}

Claude Code

Run in your terminal:

claude mcp add --transport http calculox https://www.calculox.in/api/mcp

VS Code (GitHub Copilot)

Create .vscode/mcp.json in your workspace:

{
  "servers": {
    "calculox": {
      "type": "http",
      "url": "https://www.calculox.in/api/mcp"
    }
  }
}

ChatGPT

Settings → Apps → Advanced settings → enable Developer mode, then Settings → Connectors → Create. Paste the server URL above, set Authentication to None.

Available tools

Every tool validates input the same way its calculator page does and returns a structured result. Click a tool's name to see the matching calculator on the site.

calculate_emi

Calculate EMI (equated monthly instalment), total interest and total payable for a loan given principal, annual interest rate and tenure in years. Uses the same reducing-balance formula as calculox.in/emi-calculator.

Widget
calculate_sip

Project the future value of a monthly SIP (systematic investment plan) given monthly investment amount, expected annual return, tenure in years, and an optional annual step-up percentage. Uses the same calculation as calculox.in/sip-calculator.

Widget
calculate_bmi

Calculate Body Mass Index and weight category (underweight/normal/overweight/obese) from height and weight. Uses the same calculation as calculox.in/bmi-calculator.

Widget
calculate_income_tax

Calculate Indian income tax liability for FY 2025-26 under both the old and new tax regimes, compare them, and recommend the better one, given salary details and itemized deductions (80C, 80D, HRA, home loan interest, etc.). Uses the same engine as calculox.in/tax-calculator. Fields you are unsure about can be set to 0.

Widget
calculate_fd

Calculate FD maturity value and interest earned given principal, annual interest rate, tenure, payout type (cumulative/quarterly/monthly), and senior citizen status. Uses the same calculation as calculox.in/fd-calculator.

calculate_rd

Calculate RD maturity value and interest earned given monthly deposit amount, annual interest rate, and tenure in months. Uses the same calculation as calculox.in/rd-calculator.

calculate_gst

Add or remove GST (5/12/18/28%) from an amount and get the CGST/SGST/IGST breakdown. Uses the same calculation as calculox.in/gst-calculator.

calculate_cagr

Calculate Compound Annual Growth Rate (CAGR) given a beginning value, ending value, and number of years. Uses the same calculation as calculox.in/cagr-calculator.

calculate_simple_interest

Calculate simple interest and total payable given principal, annual interest rate, and tenure (in years, months, or days). Uses the same calculation as calculox.in/simple-interest-calculator.

calculate_percentage

Six percentage calculation modes: percent-of, what-percent, percent-change, hike-discount, reverse-percent, and sequential (compound) percentage changes. Uses the same calculation as calculox.in/percentage-calculator.

calculate_profit_margin

Calculate selling price, GST, and profit margin/markup for a product given cost price and a target margin or markup percentage (or work backward from a known selling price). Uses the same calculation as calculox.in/profit-margin-calculator.

calculate_retirement_corpus

Calculate the retirement corpus required and the monthly SIP needed to reach it, using the NISM 4-step inflation-adjusted framework, given age, expenses, savings, and expected returns. Uses the same calculation as calculox.in/retirement-calculator.

calculate_home_loan_vs_rent

Compare buying a home (with a loan) against renting and investing the difference, given property price, loan terms, rent, and expected investment returns. Returns the recommended option, projected net worth for each, and the break-even year. Uses the same calculation as calculox.in/home-loan-vs-rent.

calculate_expression

Evaluate a math expression: standard arithmetic, trigonometry (sin/cos/tan and inverses), logarithms, roots, and factorial via fact(n). Uses the same evaluator as calculox.in/scientific-calculator (expression-evaluation mode only — matrix, statistics, and multi-argument functions like nCr/nPr are not exposed here).

Blog resources

All 24 guides from the calculox blog are also available as MCP resources (blog://calculox/<slug>), for a model to reference alongside a tool call — e.g. reading the EMI guide while also callingcalculate_emi.

How results are verifiedExplore the calculators →