EP QTc is the ultimate QTc (and QTp) calculator.  It is based on a framework of QTc formulas, and is as inclusive and detailed as possible.  The QTc framework is written in Swift and can be incorporated into your own MacOS or iOS apps.  EP QTc is a program written for iOS devices and the Mac, utilizing this library.  It is available for iOS devices on the App Store and for the Mac on the Mac App Store.  For more background information see the blog post  Hacking the QTc.

Get EP QTc

To use the calculator, you first enter values for the measured QT and heart rate or cycle length. You may optionally enter the sex and age, as some formulas use that information.

You then select the QTc button (or the QTp button. See Hacking the QTc to understand the difference). A list of formulas with their results will appear, color-coded as to whether they are normal, borderline or abnormal, based on the the QTc limit criteria used (see below).

Click on any formula to get details about that formula.

You can create graphs of the results. For example:

You can also see a statistical summary of the results of all the formulas:

You can select among several published criteria for determining the upper and lower limits of the QTc:

Results can be copied to the clipboard to be pasted in reports, and graphs can be saved as images. These are some of the many features of this app.

Source code for EP QTc

Source code for QTc framework

CocoaPod for the QTc framework