v0.1.1 live · open source · MIT

The personal finance engine.
For humans, websites, and AI agents.

24 deterministic calculations. 7 countries. Sharia-compliant Islamic finance. Pure Python stdlib, zero API keys.

$ pip install calcnook↗$ uvx calcnook-mcp
0Engine calcs
0Countries
0MCP tools
0Tests pass
~/calcnook · pythonv0.1.1
$ python >>> from calcnook.core.periodic_investment import calculate >>> calculate(monthly_amount=5000, annual_return=0.12, years=10).future_value 1161695.38 >>> from calcnook.countries.india.income_tax import calculate >>> calculate(1_200_000).tax_owed 0.0 # 87A rebate covers ≤ ₹12L >>> from calcnook.core.islamic.zakat import calculate >>> calculate(cash=500000).zakat_due 12500.0 >>> from calcnook.core.loan_payment import calculate >>> calculate(principal=2_500_000, annual_rate=0.085, years=20).monthly_payment 21695.58

Real engine output · MIT on GitHub · PyPI

Hot

how to use it

Same brain. Three surfaces.

Pick whichever fits how you work — calcnook is the same engine underneath all three.

For humans

Open the right calculator. Done.

100+ tools tuned for India + global personal finance. Zero login. No ads on the math. Mobile-first.

calcnook.com/income-tax-calculator
calcnook.com/sip-calculator
calcnook.com/home-loan-emi-calculator
See all calculators↓
For websites

pip install once, embed anywhere.

Pure-Python stdlib package on PyPI. No API keys, no network. Drop into Django/Flask/FastAPI.

pip install calcnook

from calcnook.countries.india.income_tax import calculate
tax = calculate(1_200_000).tax_owed
View on PyPI→
For AI agents

MCP server. 17 finance tools.

Plug into Claude, Cursor, Goose, Continue. Agents get deterministic tax/EMI/SIP/Zakat tools — no hallucinated math.

{
  "mcpServers": {
    "calcnook": { "command": "uvx", "args": ["calcnook-mcp"] }
  }
}
View MCP server→

Built global

Tax + payroll across 7 countries

Country-specific brackets, allowances, and statutes — not generic formulas.

🇺🇸

US

Federal tax · 401(k) · Roth IRA

🇬🇧

UK

Income tax · NI · personal-allowance taper

🇨🇦

CA

Federal tax · BPA credit

🇦🇺

AU

Income tax · Medicare · HECS-HELP

🇦🇪

AE

EOSG (Decree-Law 33/2021) · 5% VAT

🇸🇦

SA

EOSG · 15% VAT · ZATCA Zakat

🇮🇳

IN

FY 25-26 new regime · 87A · electricity slabs

moat · sharia compliant

Islamic finance — first-class.

Six instruments. Built into the same library. AAOIFI Sharia screening for stocks.

Zakat al-Mal

Across all asset classes

Murabaha

Cost-plus financing

Ijarah

Lease-to-own

Mudarabah

Profit-sharing

Hajj savings

Target-based pilgrimage

Halal screen

AAOIFI Sharia stocks

Serves 1.5B+ Muslims globally · no major calculator site does this end-to-end.

install

Same engine, three surfaces.

shell · python
pip install calcnook

# example — India tax with new regime
from calcnook.countries.india.income_tax import calculate
result = calculate(1_500_000)
print(result.tax_owed)        # 97500.0
print(result.effective_rate)  # 0.065

Pure stdlib · 307 tests · MIT · Python 3.10+

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