VO2 Max Calculator vs Open
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
VO2 Max Calculator
This app calculates your VO2 Max in just 3 minutes using a simple heart rate method. It's based on scientific research and provides general health information, not medical advice.
- Passive VO2 Max reading
- 3-minute calculation
- Based on scientific research
- General health information
- Video tutorial available
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Lay down and take a VO2 Max reading. 3 mins. Simple. How is this done? Read this published scientific paper by UTH N., SORENSEN H., OVERGAARD K., PEDERSEN PK. (2004) Estimation of VO2max from the ratio between HRmax and HRrest--the Heart Rate Ratio Method. Eur J Appl Physiol. Jan;91(1):111-5. For help watch this video https://youtu.be/lV5oyoW213A or contact me on https://twitter.com/ZoneTrainingApp/ for help. Note: This is not a medical test, and data use to calculate VO2Max is calibrated against the average population. Medical disclaimer: The medical/health information is provided for general informational and educational purposes only and is not a substitute for professional advice. Accordingly, before taking any actions based upon such information, we encourage you to consult with the appropriate professionals. We do not provide any kind of medical/health advice. THE USE OR RELIANCE OF ANY INFORMATION CONTAINED ON OUR MOBILE APPLICATION IS SOLELY AT YOUR OWN RISK.
Open
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Open-OH: supporting you on your journey with Long Covid, Fibromyalgia, ME/CFS and more. Track your symptoms, and engage with resources to help you increase your functional capacity and make informed decisions about your condition and occupation DIARIES Track your activity levels, sleep, meals, symptoms and more ASSESSMENTS Access industry standard, condition specific Patient Reported Outcome Measures (PROMs) RESOURCES Receive personalised suggestions to access lots of support resources to educate and guide you on your journey with your long term conditions. Including symptoms specific resources, financial guides, and advice for your manager or employer. FIND SUPPORT Find local services to support your journey
Screenshots
Verdict
The clearest difference is price: Open at Free against VO2 Max Calculator's $1.99. Open also leads on update cadence (every 2 weeks vs every 7 months). On ads, in-app purchases, device support and iOS requirement 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
Open is free to download; VO2 Max Calculator costs $1.99 up front. Neither carries in-app purchases, so what you see is what you pay.
VO2 Max Calculator ships an update every 7 months, Open every 2 weeks. The most recent releases landed on November 3, 2026 and October 27, 2026 respectively.
| Parameter | VO2 Max Calculator | Open |
|---|---|---|
| Price | $1.99 | Free — better |
| Rating | 2.4 (14 ratings) — better | — |
| Positive reviews | 38.5% of reviews | — |
| Number of ratings | 14 — better | — |
| Update frequency | Every 7 months | Every 2 weeks — better |
| Ads | No | No |
| In-app purchases | No | No |
| Monetization | Paid | — |
| Devices | iPhone, iPod, Apple Watch | iPhone, iPad, iPod |
| Requires iOS | 15.6 | 15.0 — better |
| Further details — not scored | ||
| Size | 1 MB | 30 MB |
| Age rating | 4+ | 4+ |
| Developer | Theo Scott | Elaros |
In-app purchases
VO2 Max Calculator
No in-app purchases
Open
No in-app purchases
