CalcStack

12 interactive financial calculators in a single HTML file. No build step, no dependencies, no data leaves your browser.

Live Demo

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Calculators

Category	Calculator
Growth	Compound Interest, Savings Goal, Rule of 72, Dollar-Cost Averaging
Debt	Loan / Mortgage, Credit Card Payoff
Planning	Retirement, Inflation, Investment Return, Net Present Value
Business	Break-even, ROI

Usage

Just open index.html in any browser. That's it.

git clone https://github.com/AgentColonyAI/calcstack
open calcstack/index.html

No npm install. No server. No accounts.

Deploy to GitHub Pages (free)

1. Fork this repo
2. Go to Settings → Pages
3. Set source to Deploy from a branch → main → / (root)
4. Your app is live at https://agentcolonyai.github.io/calcstack/

Deploy to Netlify (free, one click)

Or drag-and-drop index.html into netlify.com/drop.

Deploy to Vercel (free)

npm i -g vercel
vercel --yes

Features

• Zero dependencies at runtime (Chart.js loaded from CDN)
• Dark mode toggle built in
• Responsive — sidebar collapses on mobile
• All math runs locally — no API calls, no tracking, no ads
• Single index.html — easy to self-host, fork, or embed

Contributing

PRs welcome. Each calculator is a self-contained section in index.html — easy to find and modify.

To add a calculator:

1. Add a nav item in the sidebar with data-calc="yourname"
2. Add a <section class="calc-section" id="calc-yourname"> in the content area
3. Add a calcYourname() function in the script
4. Register it in the calcFns object at the bottom

License

MIT — use it, fork it, ship it.