# Acid Plus - The ABG Calculator

> Fast, powerful acid-base data

Canonical page: [https://chrome-stats.com/d/id300521236](https://chrome-stats.com/d/id300521236)

## Overview

- **ID:** `id300521236`
- **Platform:** Apple
- **Type:** Apple app
- **Status:** Available
- **Publisher:** Free Radical Software
- **Category:** Medical
- **Rating:** 4.90 / 5 (72 ratings)
- **Version:** 3.3.1
- **Last updated:** 2022-06-14
- **First published:** 2008-12-22
- **Size:** 26 MB
- **Data as of:** 2026-09-25
- **Store listing:** [Apple App Store](https://apps.apple.com/us/app/acid-plus-the-abg-calculator/id300521236)
- **Website:** [http://www.freeradicalsoft.com](http://www.freeradicalsoft.com/)
- **Privacy policy:** [https://www.freeradicalsoft.com/privacy-policy](https://www.freeradicalsoft.com/privacy-policy)

## Description

Acid Plus - ABG Calculator is a fast, powerful acid-base tool designed for healthcare professionals. Created, designed, and used by two internal medicine doctors, it delivers quick, detailed ABG and metabolic-panel analyses with an intuitive on-device display. After testing it for free, you can unlock Acid Plus for life with a one-time purchase.

### Key features
- Fast, accurate input using the dial
- Partial and complete compensations using anion gap with delta-delta
- International support for kPa
- Ability to discern complex acid/base problems with secondary disorders
- On-the-fly derivation of anion gap, delta-delta, and base excess
- Landscape view reveals a colorful interactive acid-base graph
- Customize institution's anion gap for personalized results
- Save and recall your most recent ABG
- Works on iPhone and iPad

## Rankings

- #149,768 — Overall

## Review summary

Users praise Acid Plus for easy, detailed ABG analysis with graph visualization and history recall, making it useful in clinical settings. However, multiple reviews flag iOS compatibility issues after system updates, occasional inaccuracies in complex cases, upsell concerns, and a missing base excess/deficit parameter.

### Pros

- Easy to use / intuitive user interface
- Rich detail and transparency about how results are derived
- Graph mode / ABG spectrum visualization with manual adjustment
- Ability to recall previous ABG entries / review past analyses
- Widely used and highly regarded by clinicians as a leading ABG calculator

### Cons

- Incompatibility with latest iOS versions causing the app to become unusable
- Inaccurate results or difficulty handling complex ABG scenarios (e.g., mixed disorders)
- Upsell/redirect to external products and perceived poor value for the price
- Missing parameter (base excess/deficit) in the ABG analysis options

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Source: [Chrome-Stats](https://chrome-stats.com/d/id300521236)