Financial Calculator

Instead of building yet another spreadsheet or eyeballing compound interest in your head, this skill runs the actual formulas for loans, NPV, retirement drawdowns, and investment projections. It wraps a Python script that handles the math deterministically, which matters when you're modeling scenarios where rounding and compounding order actually affect the answer. The workflow is sensible: nail down your assumptions (rates, time horizon, compounding frequency), run the calculation, and get back both the number and the assumptions that drove it. Good for when you need to show your work or compare scenarios side by side, not for personalized financial advice.

skills.sh installs: 510
GitHub stars: 131
last updated: Aug 21, 2026

View on GitHub

Install

$ npx -y skills add dkyazzentwatwa/chatgpt-skills --skill financial-calculator --agent claude-code

Installs into .claude/skills of the current project.

Files

Financial Calculator

Use deterministic calculations instead of ad hoc spreadsheet math when the user needs precise financial outputs.

Use This For

Loan and mortgage math
Investment growth and savings goals
NPV, IRR, and payback analysis
Retirement projections and withdrawal planning
Monte Carlo style risk scenarios

Workflow

Confirm units and assumptions first: rates, compounding, time horizon, taxes, and inflation.
Use scripts/financial_calc.py as the source of truth for the computation.
Return both the answer and the assumptions that materially drive it.