Finance Calc

Business, financial, and tax calculator — MCP server + CLI.

Single command install. No cloning required.

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Install

# Run directly (no install needed)
uvx finance-calc-mcp calc "185000 * 0.21"

# Or install permanently
uv tool install finance-calc-mcp
# or: pip install finance-calc-mcp

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Use as an MCP Server

Prerequisites

Install uv if you don't have it:

curl -LsSf https://astral.sh/uv/install.sh | sh

Restart your terminal after installing, then confirm uvx works:

uvx --version

Claude Desktop

Edit your Claude Desktop config:

• macOS: ~/Library/Application Support/Claude/claude_desktop_config.json
• Windows: %APPDATA%\Claude\claude_desktop_config.json

macOS:

{
  "mcpServers": {
    "finance-calculator": {
      "command": "/bin/bash",
      "args": ["-lc", "uvx finance-calc-mcp"]
    }
  }
}

Claude Desktop on macOS is a GUI app that doesn't inherit your shell PATH. The /bin/bash -lc wrapper runs a login shell so uvx is found regardless of where uv was installed.

Windows:

{
  "mcpServers": {
    "finance-calculator": {
      "command": "uvx",
      "args": ["finance-calc-mcp"]
    }
  }
}

Restart Claude Desktop. The finance tools will appear automatically.

Claude Code (terminal)

claude mcp add finance-calculator -- uvx finance-calc-mcp

Other MCP Clients

Any MCP-compatible client can launch the server:

uvx finance-calc-mcp

With no arguments, it starts in MCP server mode (stdio transport).

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MCP Tools

When connected as an MCP server, Claude gets these tools:

calculate

Evaluate a financial/business math expression. Supports +, -, *, /, **, %, parentheses, and functions: round(), abs(), max(), min(), sum(), sqrt(), log(), floor(), ceil(), pow().

Parameter	Type	Required	Description
expression	string	yes	Math expression to evaluate

gross_margin

Calculate gross margin, gross profit, and markup from revenue and COGS.

Parameter	Type	Required	Description
revenue	number	yes	Total revenue
cogs	number	yes	Cost of goods sold

us_income_tax_estimate

Estimate 2024 US federal income tax for individuals, with bracket-by-bracket detail.

Parameter	Type	Required	Description
taxable_income	number	yes	Taxable income in USD
filing_status	string	yes	single, married_jointly, married_separately, or head_of_household

self_employment_tax

Calculate self-employment (SE) tax and deductible half for Schedule SE. Covers Social Security, Medicare, and the additional Medicare surtax above $200k.

Parameter	Type	Required	Description
net_self_employment_income	number	yes	Net profit from self-employment

depreciation

Calculate a depreciation schedule (straight-line or double-declining balance).

Parameter	Type	Required	Description
asset_cost	number	yes	Asset purchase price
useful_life	number	yes	Useful life in years
salvage_value	number	no	Salvage/residual value (default 0)
method	string	no	straight_line (default) or double_declining

payroll_summary

Estimate employer payroll costs and employee net pay for a given gross salary. Covers FICA (Social Security + Medicare), FUTA, and SUTA.

Parameter	Type	Required	Description
gross_annual_salary	number	yes	Annual gross salary
state_suta_rate	number	no	State unemployment rate % (default 2.7)

loan_amortization

Generate a loan amortization summary: monthly payment, total interest paid, and optionally a full month-by-month schedule.

Parameter	Type	Required	Description
principal	number	yes	Loan principal
annual_rate_pct	number	yes	Annual interest rate as percent (e.g. 6.5)
term_years	number	yes	Loan term in years
show_schedule	boolean	no	Return full amortization table (default false)

percent_change

Calculate percent change between two values.

Parameter	Type	Required	Description
old_value	number	yes	Starting/original value
new_value	number	yes	Ending/new value

break_even

Calculate break-even units and revenue given fixed costs, price per unit, and variable cost per unit.

Parameter	Type	Required	Description
fixed_costs	number	yes	Total fixed costs
price_per_unit	number	yes	Selling price per unit
variable_cost_per_unit	number	yes	Variable cost per unit

currency_format

Format a number as a USD currency string.

Parameter	Type	Required	Description
amount	number	yes	Amount to format
decimals	integer	no	Decimal places (default 2)

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CLI Usage

Every MCP tool is also available as a CLI command.

# Evaluate any expression
finance-calc-mcp calc "185000 * 0.21"
finance-calc-mcp calc "(850000 - 612000) / 850000 * 100"

# Gross margin
finance-calc-mcp margin 850000 612000

# 2024 US federal income tax estimate
finance-calc-mcp tax 185000 single
finance-calc-mcp tax 320000 married_jointly

# Self-employment tax
finance-calc-mcp se-tax 95000

# Loan amortization (add --schedule for full table)
finance-calc-mcp amortize 400000 6.5 30
finance-calc-mcp amortize 400000 6.5 30 --schedule

# Payroll (optional: state SUTA rate %)
finance-calc-mcp payroll 95000
finance-calc-mcp payroll 95000 3.4

# Depreciation (straight-line default, or double_declining)
finance-calc-mcp depreciation 50000 5
finance-calc-mcp depreciation 50000 5 5000 --method double_declining

# Break-even analysis
finance-calc-mcp break-even 120000 49.99 18.50

# Percent change
finance-calc-mcp pct-change 1200000 1485000

# Format as currency
finance-calc-mcp format 1234567.89

Example Output

$ finance-calc-mcp tax 185000 single

2024 Federal Income Tax Estimate (single)
Taxable Income:   $185,000.00
Federal Tax:      $37,442.50
Effective Rate:   20.24%

Bracket Detail:
  10%  $0.00 – $11,600.00:  $11,600.00 taxed → $1,160.00
  12%  $11,600.00 – $47,150.00:  $35,550.00 taxed → $4,266.00
  22%  $47,150.00 – $100,525.00:  $53,375.00 taxed → $11,742.50
  24%  $100,525.00 – $191,950.00:  $84,475.00 taxed → $20,274.00

$ finance-calc-mcp amortize 400000 6.5 30

Loan Amortization Summary
Principal:       $400,000.00
Rate:            6.500% APR
Term:            30 years (360 months)
Monthly Payment: $2,528.27
Total Paid:      $910,177.52
Total Interest:  $510,177.52
Interest/Dollar: 127.54%

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License

MIT