DEV3 Compound Interest and SIP Calculator — Source Code (React + Tailwind)

Source code of the DEV3 Compound Interest and SIP Calculator, an investment growth calculator for lump sums, SIPs and step-up SIPs with year-by-year tables, SVG charts, inflation-adjusted value and CSV export.

Download: buy a licence and the ZIP is waiting in Account → Downloads. Try it live: https://dev3.tech/tools/compound-interest-sip-calculator shows the finished tool running.

What is in the download

• A standalone Vite + React + TypeScript + Tailwind CSS project: src/tool holds the tool, shared pieces sit beside it
• package.json with exact versions plus a lockfile, so npm ci works
• README.md (run, build, embed in Next.js or plain React) and an MIT LICENSE

What the code does

• One monthly growth engine for lump sum, SIP, step-up SIP and combined plans
• Selectable compounding frequency
• Dependency-free SVG line and stacked bar charts
• CSV download of the yearly table

Tech stack

React 19, TypeScript, Vite, Tailwind CSS 4.

Install and customise

The How to install and How to use tabs list the steps. In short: unzip, npm ci, npm run dev, then copy the tool folder into your own app if you want to embed it.

Good to know

• A browser-only tool: there is no backend or database in the code.
• Projections use one constant return; they ignore fees, taxes and volatility.