# Investment.tools

> Free, browser-based investing calculators — compound interest, DCA, ROI, real estate, rent vs buy, inflation, Rule of 72/69, savings goal, mortgage payoff, and FIRE. No sign-ups, no data collection. An AXIA Enterprises property.

## Main

- [Home / Calculator Workspace](https://investment.tools/): All ten calculators run instantly in the browser using standard financial formulas, with side-by-side comparison mode, PDF export, and shareable URLs.
- [Historical Reference Data](https://investment.tools/#reference): Historical averages for S&P 500 returns, U.S. CPI inflation, 30-year mortgage rates, and real estate appreciation to help pick realistic inputs.
- [Methodology](https://investment.tools/#methodology): How the tools work, what they assume (constant rates, consistent contributions), and what they cannot tell you.
- [FAQ](https://investment.tools/#faq): Accuracy, assumptions, and how to use scenario calculators responsibly.

## For AI

- [LLM Info](https://investment.tools/llm-info): Machine-readable site description and instructions for AI assistants.
- [ai.txt](https://investment.tools/ai.txt): Crawling and usage policy for AI systems.