Airgead is a responsive, client-side compound interest calculator built to help you understand how consistent monthly contributions accelerate long-term investment growth. Enter your starting balance, monthly deposit, annual rate, and timeframe — and Airgead instantly shows you the projected difference, year by year.Documentation Index
Fetch the complete documentation index at: https://mintlify.com/apursley2012/airgead-investment-calculator/llms.txt
Use this file to discover all available pages before exploring further.
Introduction
Learn what Airgead is, what it does, and how the project is structured.
Quickstart
Run the application locally in under two minutes — no installation required.
Using the Calculator
Enter your four inputs and preview live balance projections instantly.
JavaScript API Reference
Explore the core calculation, charting, and storage functions.
What Airgead does
Airgead runs two parallel compound-interest projections from the same inputs: one where the starting balance grows on its own, and one where a recurring monthly deposit is added each month. The difference between those two paths is the central insight the application is designed to communicate.Open the Calculator
Navigate to the Calculator page and enter your starting balance, monthly deposit, annual interest rate, and number of years.
Review live results
The projected final balance updates as you type. Quick stats show the without-deposits figure and the difference created by contributing monthly.
Explore detailed results
Select View Details to see the full growth chart, year-by-year breakdown table, total principal, and earned interest.
Key features
Live Projections
Balance figures animate in real time as you adjust any of the four inputs.
Scenario Comparison
Compare two independent investment plans side by side with a shared canvas chart.
Saved Plans
Store calculations in
localStorage and revisit them from the Saved Plans page.CSV Export
Download the full year-by-year projection as a CSV file — generated entirely in the browser.
No Build Step
Plain HTML, CSS, and JavaScript ES modules. Deploy directly to GitHub Pages.
C++ Heritage
The original console application is preserved in
source/ alongside the web version.Explore the docs
How the Calculation Works
Understand the monthly compounding model, input clamping, and how principal is tracked separately from interest.
Deployment Guide
Deploy the static site to GitHub Pages in minutes with no build configuration.
Customization
Change brand colors, navigation links, calculator defaults, and add new articles.
C++ Source Overview
Review the original object-oriented console application that inspired the web version.