# Rule-Of-Three Calculator

> Proportion Calculator - direct and indirect proportions. Ad-free.

Canonical page: [https://chrome-stats.com/d/mbar.propcalc](https://chrome-stats.com/d/mbar.propcalc)

## Overview

- **ID:** `mbar.propcalc`
- **Platform:** Android
- **Type:** Android app
- **Status:** Removed
- **Publisher:** mbar Software
- **Category:** EDUCATION
- **Downloads:** 45,495
- **Rating:** 4.90 / 5 (294 ratings)
- **Version:** 2.2.934
- **Last updated:** 2021-05-13
- **First published:** 2016-05-13
- **Publisher country:** AT
- **Size:** 1.70 MB
- **Data as of:** 2026-08-16
- **Store listing:** [Google Play Store](https://play.google.com/store/apps/details?id=mbar.propcalc)
- **Website:** [https://sites.google.com/view/mbarsoftware](https://sites.google.com/view/mbarsoftware)
- **Privacy policy:** [https://sites.google.com/view/mbarsoftware/home/privacy](https://sites.google.com/view/mbarsoftware/home/privacy)

## Description

The Rule-Of-Three Calculator is part of the mbar School Tools series, designed to help students and professionals effortlessly calculate proportions using the classic rule of three. By entering three known values, the tool quickly computes the missing fourth value, whether it involves direct or indirect proportions.

Version 2.0 introduces a powerful feature that displays the detailed formula after each calculation, enhancing your understanding and learning experience. The app also keeps a history of all your calculations for easy review and management. With a clean, ad-free interface and support for Dark Mode, this extension is both user-friendly and visually adaptable. Perfect for educational and professional use, the Rule-Of-Three Calculator requires no special permissions and is free to use.

## Permissions and access

### Permissions

- `android.permission.ACCESS_NETWORK_STATE`
- `android.permission.ACCESS_WIFI_STATE`
- `android.permission.INTERNET`
- `android.permission.VIBRATE`
- `android.permission.WAKE_LOCK`

## Review summary

Users appreciate the Rule-Of-Three Calculator for its simplicity, usability, and ad-free experience. It is valued for practical, quick, and accurate proportion calculations both at work and home. Some users suggest adding features like percentage increase calculations and detailed solution steps to improve functionality.

### Pros

- Simple and easy to use
- Very useful and practical for quick calculations
- No advertisements, small app size
- User-friendly interface
- Features like history function and options for comparing items

### Cons

- Lacks percentage increase feature desired by some users
- Does not provide full solutions or explanations for calculations (direct and inverse proportions)

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Source: [Chrome-Stats](https://chrome-stats.com/d/mbar.propcalc)