Content
# Axiom Calculator MCP
Personal finance calculators for Claude and AI agents — mortgage payments, compound interest, FIRE retirement number, loan comparison, debt payoff, and inflation-adjusted returns.
**Zero API keys. Zero setup. Works instantly with any MCP client.**
[](https://pypi.org/project/axiom-calculator-mcp/)
[](https://opensource.org/licenses/MIT)
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## Tools (8 total)
| Tool | What it does |
|------|-------------|
| `mortgage_calculator` | Monthly payment, total interest, 12-month amortization schedule |
| `rent_vs_buy` | Compare total cost of renting vs buying over N years (includes equity, appreciation, opportunity cost) |
| `compound_interest` | Project investment growth with optional monthly contributions — year-by-year table |
| `fire_number` | Calculate your FIRE target portfolio and years-to-retirement timeline |
| `inflation_adjusted_return` | Real vs nominal return — see if your investments actually beat inflation |
| `loan_comparison` | Compare two loans by total cost, monthly payment, and true APR (including fees) |
| `true_credit_cost` | Find the real APR of any financing offer, BNPL, or credit product |
| `debt_payoff_plan` | Payoff timeline and interest saved from extra monthly payments |
---
## Install
### Claude Desktop / Claude Code
Add to your MCP config:
```json
{
"mcpServers": {
"calculator": {
"command": "uvx",
"args": ["axiom-calculator-mcp"]
}
}
}
```
### Any MCP client (stdio)
```bash
uvx axiom-calculator-mcp
```
### From source
```bash
git clone https://github.com/vdalhambra/axiom-calculator-mcp
cd axiom-calculator-mcp
uv run axiom-calculator
```
---
## Example usage
Once connected, just ask Claude naturally:
> *"I'm looking at a $450,000 house with 20% down at 6.8% for 30 years. What's my monthly payment and total interest?"*
> *"Compare a 15-year loan at 6.2% vs 30-year at 6.8% for $380,000. Which is better overall?"*
> *"I spend $48,000/year. How much do I need to retire, and how long will it take if I save $24,000/year?"*
> *"I have $8,500 in credit card debt at 22% APR. How long to pay it off at $250/month, and how much do I save if I add $100/month extra?"*
---
## Why this exists
Most finance calculators are either locked behind paywalls, require accounts, or are ad-stuffed websites. This MCP gives Claude direct access to accurate financial math — no API keys, no rate limits, no middleman.
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## Part of the Axiom MCP suite
- [FinanceKit MCP](https://github.com/vdalhambra/financekit-mcp) — Stock quotes, fundamentals, crypto, insider transactions
- [SiteAudit MCP](https://github.com/vdalhambra/siteaudit-mcp) — SEO audits, Core Web Vitals, backlink analysis
---
## License
MIT — free to use, modify, and distribute.
