Comparison

Hematox vs QTc

Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.

Head to head
About

Hematox

Features
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Hematox®, a bibliographical databank based on drug-induced blood disorders, was created in 1983 by Michel BIOUR (MD, PhD), and monthly updated in accordance with other bibliographical databases to the analysis of the references cited in the articles. All the published cases for selection and classification were re-evaluated in accordance with criterions usually validated in hematology. 1069 drugs are registered with 15126 corresponding and available references. Anticancer drugs and immunomodulators, well known for their intrinsic hematotoxicity, are not indexed in Hematox.

About

QTc

This medical app calculates QTc using nine different formulas. It allows users to input heart rate or RR interval and QT interval length for quick results. An Apple Watch app is also included for convenient access.

Highlights
  • Nine QTc calculation formulas
  • Input heart rate or RR interval
  • Input QT interval length
  • Apple Watch app integration
  • No personal data collection
  • Offline functionality
Read full description

QTc Calculator corrects the QT interval for heart rate, with nine published formulas at once instead of just one. Bazett is still the formula most ECG machines use, but it overestimates the QTc at higher heart rates and underestimates it at lower ones. QTc Calculator shows you right away how the result changes with other formulas, and where it sits relative to published reference limits and population data. FORMULAS Bazett, Fridericia, Framingham, Hodges, Rautaharju (two versions), Mayeda, Kawataki and Goto, side by side. Choose which formulas you want to see and in which order. Each result comes with a chart of the QTc distribution in the general population (Vandenberk et al. 2016) and a short note on the formula's strengths and weaknesses. START FROM QT OR FROM QTc Enter heart rate (or RR interval) and QT, or start from a QTc printed by the ECG machine. The app calculates the QT back from the formula the QTc came from and converts it to all other formulas. J-POINT CALCULATIONS With a QRS duration, the app adds the JT interval, the heart-rate-corrected JTrr (Rautaharju) and the JTc of each formula. For wide QRS complexes, such as in bundle branch block, it shows QTmc (Bogossian). REFERENCE LIMITS Results are color-coded against the short and long QT limits of your choice: ESC 2022, ESC 2015, AHA 2009, ESC 2005, FDA 2005, Gollob 2011, Mazzanti 2014, Goldenberg 2006 (including limits for children and adolescents) and Schwartz 1985/1993. Separate limits for women and men. SCORES • Gollob Score for Short QT Syndrome • Long QT Score (Schwartz, as in the ESC guidelines 2022) • Tisdale Score for the risk of drug-induced QT prolongation in hospitalized patients All scores open with the points for the QTc you just calculated. BASELINE COMPARISON Enter a previous ECG as a baseline. The app marks it in every chart and tells you when the QTc has increased by more than 60 msec. MADE FOR DAILY USE • Plausibility checks catch typos and unusual values right below the input field. • Notices for heart rates outside the range where QTc formulas are most reliable. • A guide to measuring the QT interval correctly (threshold and tangent method). • Share or copy a summary of all results. • Two-column layout on iPad and on iPhone Duo when unfolded. • Color-blind mode (blue instead of green). • English and German. PRIVACY No account, no ads, no tracking. The app does not connect to the internet. Your inputs stay on your device. ALL SOURCES INCLUDED Every formula, limit and score names its literature source. All references are listed in the app. IMPORTANT QTc Calculator is a calculation and reference tool for healthcare professionals. It does not provide medical advice, diagnosis or treatment recommendations and does not replace clinical judgment. 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.

Screenshots

Hematox4 screens
QTc4 screens

Verdict

The call

The clearest difference is price: QTc at Free against Hematox's $3.99. Hematox's advantage is iOS requirement (16.0 vs 27.0). On update cadence, ads, in-app purchases and device support there is nothing between them.

Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS

CostPrice · In-app purchases · Ads · Monetization

QTc is free to download; Hematox costs $3.99 up front. Neither carries in-app purchases, so what you see is what you pay.

UpkeepUpdate frequency

Hematox ships an update every 3 months, QTc every 4 months. The most recent releases landed on October 8, 2026 and October 26, 2026 respectively.

Scorecard2 real differences · 8 level
Hematox versus QTc: the parameters behind the verdict, then further details
ParameterHematoxQTc
Price$3.99Free — better
Rating—4.7 (51 ratings) — better
Positive reviews—50.0% of reviews
Number of ratings—51 — better
Update frequencyEvery 3 months — betterEvery 4 months
AdsNoNo
In-app purchasesNoNo
Monetization—Free
DevicesiPhone, iPadiPhone, iPad
Requires iOS16.0 — better27.0
Further details — not scored
Size1 MB1 MB
Age rating17+17+
DeveloperPierre ChailletMarian Stiehler

In-app purchases

None

Hematox

No in-app purchases

None

QTc

No in-app purchases

Questions

Is Hematox free?
Hematox costs $3.99, with no in-app purchases.
Is QTc free?
QTc is free to download, with no in-app purchases.
Do Hematox or QTc have ads?
Neither Hematox nor QTc shows ads.
Which is updated more often, Hematox or QTc?
Hematox ships an update every 3 months, and QTc every 4 months. Most recently, Hematox was updated on October 8, 2026 and QTc on October 26, 2026.

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