Rule of Three Calculator helps you solve direct proportions quickly, clearly, and comfortably on your phone. Enter three values and get the fourth result instantly. The app keeps the classic rule-of-three layout in a clean 2x2 grid, so each calculation is easy to understand at a glance and convenient to use for both quick checks and repeated tasks. It is designed for people who want simple calculations without extra steps or unnecessary clutter. It can be useful for study, shopping, cooking, work, measurements, percentages, conversions, and everyday math. Main features: - Fast direct proportion calculations - Clean and easy-to-read design - Instant result display - Local history saved on the device - Reuse previous calculations - Delete individual entries or clear all history - Simple use with no account or sign-in Your history stays on your device, so you can review recent calculations and remove them whenever you want.