# ECG Caliper — Measure ECG intervals

> Measure ECG intervals like PR, RR, and QTc from images. (iPhone/iPad app by Mathias Tschopp.)

- Source: https://appshunter.io/ios/app/ecg-caliper/id1498225344 (this page in markdown: same URL + `.md`)
- Developer: [Mathias Tschopp](https://appshunter.io/developer/299470334)
- Category: Medical, Health & Fitness
- Price: Free
- Rating: 2.30/5 from 3 App Store ratings
- Age rating: 17+
- Requires: iOS 14.1 · 6 MB
- Languages: American English, French (France)
- Released: 2020-02-25
- Data updated: 2026-06-10
- Monetization: free
- User reviews in markdown: https://appshunter.io/ios/app/ecg-caliper/id1498225344/reviews.md

## What is ECG Caliper?

This application allows you to measure intervals in ECGs that you capture with the camera, or import from the Photo Library. Intervals such as PR, RR or QTc can be easily measured, at any level of zoom.

Features:
• Scan ECG directly into the app with iOS Document Scanning support
• Once calibrated, intervals can be measured at any level of zoom
• QTc can be easily calculated, as well as PR and RR intervals
• A grid can be overlaid on top to check for regularity of rythm, or repeating patterns
• Once calculated, intervals are automatically copied to the clipboard for easy export 

How it works:
ECGs are recorded with a paper speed of 25 mm per second. That means that the distance on screen between 2 points can be translated into a duration, once calibration is achieved. 
The distance between two points in the ECG will then be displayed in millisecond (ms) and can be recorded. QTc can be computed using the Bazett formula.

Disclaimer:
No medical decision regarding diagnosis or treatment should be taken on the basis of results provided by this app without seeking professional medical advice.

## Key features

- Measure ECG intervals (PR, RR, QTc)
- Import ECGs via camera or photo library
- Zoom functionality for precise measurements
- Overlay grid for rhythm analysis
- Automatic clipboard copying of results
- QTc calculation using Bazett formula


## Frequently asked questions about ECG Caliper

### How does ECG Caliper measure ECG intervals?

ECG Caliper measures intervals by translating the distance between two points on an ECG image into a duration in milliseconds, assuming a standard paper speed of 25 mm per second. Calibration is required for accurate measurements.

### What types of ECG intervals can ECG Caliper measure?

ECG Caliper can measure PR intervals, RR intervals, and QTc intervals. The QTc interval is calculated using the Bazett formula.

### Can I import ECGs into ECG Caliper?

Yes, you can import ECGs into ECG Caliper either by scanning them directly into the app using iOS Document Scanning support or by importing them from your Photo Library.

### Does ECG Caliper have ads?

The provided data does not specify if ECG Caliper contains advertisements. However, it is listed as free with no in-app purchases.

### What devices is ECG Caliper compatible with?

ECG Caliper is compatible with iPhone, iPad, and iPod devices. It is rated for users aged 17 and older.

### How often is ECG Caliper updated?

The latest version of ECG Caliper is 4.0, which was last updated on August 20, 2022. The app was initially released on February 25, 2020.

### What is the user rating for ECG Caliper?

ECG Caliper has a rating of 2.3 stars based on 3 user ratings. This suggests a mixed to negative user sentiment.

### Is ECG Caliper suitable for medical diagnosis?

No, ECG Caliper is not intended for medical diagnosis or treatment decisions. Users should always seek professional medical advice for any health concerns.

## Version history (last 5 releases)

### 4.0 — 2022-08-20

• QRS duration
• Choice of several formulas to calculate QTc

### 3.2 — 2022-05-25

Bug fixes

### 3.1 — 2021-11-02

• added heart rate calculator (beneath interval indicator)
• refreshed look for buttons
• added support for importing live pictures from camera roll

### 3.0 — 2021-02-08

- easier method for calibration
- refreshed look for caliper tools
- new grid menu with ability to change grid color and spacing
- bug fixes

### 2.1 — 2020-09-29

Fix issue with Dynamic Type making calculated results unreadable.

## Apps similar to ECG Caliper

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| --- | --- | --- | --- |
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## More apps by Mathias Tschopp

- [Times x Tables](https://appshunter.io/ios/app/times-x-tables/id1165102802)
- [Case Collection](https://appshunter.io/ios/app/case-collection/id1462054506)

All apps by Mathias Tschopp: https://appshunter.io/developer/299470334

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*Data collected daily from the US App Store and indexed by [AppsHunter](https://appshunter.io/). User reviews are verbatim App Store reviews. Ratings, prices and chart positions refresh continuously; this snapshot is from 2026-06-10.*