# QTc-Calculator — ECG calculator > Medical ECG calculator for QTc using nine distinct formulas. (iPhone/iPad app by Marian Stiehler.) - Source: https://appshunter.io/ios/app/qtc-calculator/id1354439139 (this page in markdown: same URL + `.md`) - Developer: [Marian Stiehler](https://appshunter.io/developer/1354439138) - Category: Medical - Price: Free - Rating: 4.70/5 from 51 App Store ratings · 4 written reviews indexed - Age rating: 17+ - Requires: iOS 18.0 · 1 MB - Languages: American English, German (Germany) - Released: 2018-03-10 - Data updated: 2026-08-01 - Monetization: free - User reviews in markdown: https://appshunter.io/ios/app/qtc-calculator/id1354439139/reviews.md ## What is QTc? Nine formulas! Apple Watch App! This app enables doctors to calculate QTc quickly. You can enter either the heart rate or the length of the RR interval, and the length of the QT interval. There will be results for QTc for the following formulas: Bazett's, Fridericia's, Framingham's, Hodges's, Goto's, Mayeda's, Kawataki's, Rautaharju's a and b. Also, RR interval or heart rate and estimates of QT depending on heart rate are determined. An Apple Watch app is also included. PRIVACY: This app does not collect any personal data. No connections to a server will be made. Please note: This app provides only information, is not medical or treatment advice and may not be treated as such by the user. As such, this App may not be relied upon for the purposes of medical diagnosis or as a recommendation for medical care or treatment. The information on this App is not a substitute for professional medical advice, diagnosis or treatment. All content, including text, graphics, images and information, contained on or available through this App is for general information purposes only. Professional Medical Advice and Assistance You are strongly encouraged to confirm any information obtained from or through this App with your physician or another professional healthcare provider and to review all information regarding any medical condition or treatment with your physician or other a professional healthcare provider. No Reliance YOU MUST NEVER RELY ON ANY INFORMATION OBTAINED USING THIS APP FOR ANY DIAGNOSIS OR RECOMMENDATION FOR MEDICAL TREATMENT. YOU MUST NEVER RELY ON THE INFORMATION RECEIVED FROM THIS APP AS ALTERNATIVE TO MEDICAL ADVICE FROM YOUR PHYSICIAN OR OTHER PROFESSIONAL HEALTHCARE PROVIDER.\n\nYOU MUST NEVER DISREGARD PROFESSIONAL MEDICAL ADVICE OR DELAY SEEKING MEDICAL TREATMENT AS RESULT OF ANY INFORMATION YOU HAVE SEEN ON OR ACCESSED THROUGH THIS APP. IF YOU HAVE ANY SPECIFIC QUESTIONS ABOUT ANY MEDICAL MATTER YOU SHOULD CONSULT YOUR PHYSICIAN OR OTHER PROFESSIONAL HEALTHCARE PROVIDER. IF YOU THINK YOU MAY BE SUFFERING FROM ANY MEDICAL CONDITION YOU SHOULD SEEK IMMEDIATE MEDICAL ATTENTION. No Warranty The information provided by this App is provided “as is” without any representations or warranties, express or implied. iProvèn makes no representations or warranties in relation to the medical or other information in this App. ## Key features - Nine QTc calculation formulas - Input heart rate or RR interval - Input QT interval length - Apple Watch app integration - No personal data collection - Offline functionality ## Recent user reviews (4 of 4) All indexed reviews: https://appshunter.io/ios/app/qtc-calculator/id1354439139/reviews.md ### 5/5 — Sehr toll *2022-11-18, version 5.0* Finde die App wunderbar. Medizinisch bestmöglich. Wünschenswert wäre natürlich eine Integration mit Apple Watch. Das kann ich aber natürlich bei einer Gratis App nicht verlangen. Also volle ⭐️⭐️⭐️⭐️⭐️ ### 1/5 — Says Apple watch app included *2020-11-29* I'm not sure what your supposed to put in the fields, but the way it is described, if you have an apple watch, the app will tell you your qt interval when you do an ecg. What a waste of time and money. ### 3/5 — Too advanced for lay folk *2020-06-24* I just don't know what is good or bad. Seems convenient. But it is beyond my grssp and I have four college degrees, hustt not iin anything about medicing. ### 5/5 — Der beste QTc-Rechner im Store *2019-01-25, version 2.1* Schnell, bedient sich super, funktioniert top. ## Frequently asked questions about QTc ### What is QTc-Calculator used for? QTc-Calculator is used by medical professionals to quickly calculate the corrected QT interval (QTc) using nine different formulas. It helps in assessing cardiac repolarization. ### Does QTc-Calculator collect personal data? No, QTc-Calculator does not collect any personal data and does not make any connections to a server. Your privacy is maintained as no personal information is stored or transmitted. ### What formulas are included in QTc-Calculator? QTc-Calculator includes nine formulas for QTc calculation: Bazett's, Fridericia's, Framingham's, Hodges's, Goto's, Mayeda's, Kawataki's, and Rautaharju's a and b. ### Is QTc-Calculator available on Apple Watch? Yes, QTc-Calculator includes a dedicated Apple Watch app, allowing for convenient QTc calculations directly from your wrist. ### What devices does QTc-Calculator support? QTc-Calculator supports iPhone and iPad devices. It is designed for use on Apple's mobile and tablet platforms. ### How often is QTc-Calculator updated? The latest version of QTc-Calculator is 8.0, and it was last updated on December 21, 2025. This indicates a commitment to ongoing development and improvements. ### What is the age rating for QTc-Calculator? QTc-Calculator has an age rating of 17+. This is typical for medical applications that require a certain level of understanding and professional context. ### Can QTc-Calculator be used for medical diagnosis? No, QTc-Calculator explicitly states that it provides information only and is not medical or treatment advice. It should not be relied upon for diagnosis or treatment recommendations. ## Version history (last 5 releases) ### 8.0 — 2025-12-21 - add comparison value - new icon - mode for red green blindness ### 6.0 — 2024-11-03 - Bug fixes - New Accent Color (red) - The keyboard is now dismissible by swiping ### 5.2 — 2024-03-30 - privacy information added (This app has never and will never collect any data about you. It does not open a connection to the internet.) - you can contact the developer now via email ### 5.0 — 2022-09-17 Complete Rewrite of the app with population data ### 4.2 — 2020-04-14 - new icons in the tab bar - bug fix for iPhone 11 Pro Max ## Apps similar to QTc | App | Rating | Price | Category | | --- | --- | --- | --- | | [ECG+ \| Your Watch ECG Reader](https://appshunter.io/ios/app/ecg-plus-your-watch-ecg-reader/id1567047859) | 4.5 (2,358) | Free | Medical | | [артериальное давление SmartBP](https://appshunter.io/ios/app/smartbp/id519076558) | 4.5 (58,097) | Free | Medical | | [ECG Test for Doctors](https://appshunter.io/ios/app/ecg-test-for-doctors/id757666618) | 4.7 (392) | Free | Medical | | [ECG EKG Interpretation Mastery](https://appshunter.io/ios/app/ecg-ekg-interpretation-mastery/id1143682180) | 4.5 (671) | Free | Medical | | [Blood Pressure App: Log Diary](https://appshunter.io/ios/app/blood-pressure-app-log-diary/id1525183703) | 4.2 (98) | Free | Medical | | [ManageAnticoag](https://appshunter.io/ios/app/manageanticoag/id1158887101) | 4.8 (6) | Free | Medical | ## More apps by Marian Stiehler - [International Health Passport](https://appshunter.io/ios/app/international-health-passport/id1503976605) All apps by Marian Stiehler: https://appshunter.io/developer/1354439138 ## Related topics [ecg calculate](https://appshunter.io/ios/topics/ecg-calculate) · [qaly](https://appshunter.io/ios/topics/qaly) · [qtc calculadora simples](https://appshunter.io/ios/topics/qtc-calculadora-simples) --- *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 2026-08-01.*