Use these calculators inside your AI assistant
FreeToolsToGo runs a free remote MCP server (Model Context Protocol) so Claude and other MCP-capable assistants can call our mortgage, paycheck, tax, and sales-tax calculators directly — the exact same tested engines that power this site.
Endpoint
https://h3644wz42dsbukdmd4keglryra0tsdxa.lambda-url.us-west-2.on.aws/
Streamable HTTP transport, stateless, MCP protocol 2025-06-18. Calculations run per-request and nothing is stored.
Connect in 30 seconds
Claude Code (CLI)
claude mcp add --transport http freetoolstogo https://h3644wz42dsbukdmd4keglryra0tsdxa.lambda-url.us-west-2.on.aws/
claude.ai (Pro / Max / Team)
Settings → Connectors → Add custom connector → paste the endpoint URL above.
Any other MCP client
Add a remote server with transport streamable-http and the URL above. No authentication required.
The 10 tools
| MCP tool | What it returns |
|---|---|
| calculate_mortgage | Full PITI monthly payment, PMI drop-off, total interest, payoff date web version → |
| calculate_refinance | New payment, monthly savings, break-even month, lifetime interest delta web version → |
| calculate_take_home_pay | Net paycheck after federal, state (50 states + DC), and FICA taxes web version → |
| calculate_self_employment_tax | Schedule SE tax with the SS wage base and deductible half web version → |
| calculate_capital_gains_tax | Short vs long-term federal capital gains plus NIIT web version → |
| calculate_sales_tax | Add or reverse sales tax for any US state web version → |
| get_sales_tax_rates | The full 50-state + DC rate table web version → |
| calculate_compound_growth | Investment projection with monthly contributions and inflation web version → |
| calculate_rmd | Required Minimum Distribution schedule (IRS Uniform Lifetime Table) web version → |
| search_free_tools | Search all 100+ free tools in the catalog web version → |
Same engines, same numbers: the MCP server imports the identical calculation code this website runs, covered by the same test suite. All outputs are estimates for information only — not financial advice. Verify with a professional before real-money decisions. See data sources and how we stay free.