# Commercial Gas Calculator — user reviews > 17 indexed App Store user reviews of Commercial Gas Calculator by Oliver Shingler. - Source: https://appshunter.io/ios/app/commercial-gas-calculator/id997737518/reviews - App overview in markdown: https://appshunter.io/ios/app/commercial-gas-calculator/id997737518.md ## Most critical reviews (10 lowest-rated) ### 1/5 — Absolute rubbish *2025-07-24* Doesn’t do anything lets you put measurements in then wont add to system tried on iPhone and ipad same results zero **Developer response:** I have just tested on an iPhone 14 Pro, 16 Pro and an 11-inch iPad Pro (M4), all running iOS 18.5. I can't find any issues with adding pipe lengths to the system, it all appears to be working fine. Could you please let me know your device and iOS version so as I can try and replicate your issue please? You can contact me via my web site here: https://www.speaktothegeek.co.uk/support-and-contact-info ### 1/5 — Could be so much better *2020-03-15* Yes the calculator gives TTD but the calculations above do no indicate IVmeter so does not give IV to total I expected the calculator to allow for maximum permissible leak rates, but sadly it just works out the purge volume and TTD although given i had to manually work out to see if it was correct NO TTP nor let by period Unfortunately the app is sadly lacking however it does work out the pipe volume correctly ! ### 1/5 — Not Great. *2020-03-09* Does not offer standard UK sizes for pipework or even press systems. No 35mm, 54mm, 66.7mm etc etc Update, I was referring to press systems, Mapress, Xpress, M-Press etc etc What about Stainless or Carbon Press? Copper and barrel are old hat these days **Developer response:** This app is specifically targeted at the UK with UK specific sizes listed for pipework, including copper pipes with a diameter of 35mm, 54mm and 67mm. ### 1/5 — Dangerously inaccurate *2019-12-19* Bought this in the hope that all the other reviews were wrong and somehow it would be ok for me, tested it on a tightness test that I had already calculated, true system volume was 0.95xxxm3, the app came out with 0.85xxxm3 and said the test time would be..... 2 minutes!!!! **Developer response:** Hi, could you please contact me at support@speaktothegeek.co.uk with your worked example so as I can reproduce the problem. Your assistance in resolving this will be greatly appreciated as current test scenarios are not showing any errors. ### 1/5 — RIP OFF!! *2019-12-18* Load of rubbish!!!! Will be asking for my money back!!! Not paying every time I want a calculation! Much rather pay £50.00 for one that works every time and not charge for the results each time! Do not buy!! It’s a scam! They don’t tell you that you need to pay for each result!! **Developer response:** This is not true, you do not have to pay for each calculation. Included with the purchase of the app is unlimited calculations of purge times. If you would like the tightness testing duration then this can be unlocked in-app for unlimited calculations as a one-time purchase. ### 1/5 — Very carefully not good apps *2018-08-26* Dear buyers be careful from this apps because not good at all. I Used this apps for couple weeks suddenly I realised the calculation is in correct. From now I am using my book. ### 1/5 — Disappointed *2018-04-09* What a load of rubbish cannot believe Ho bad !!!! **Developer response:** Any particular reason why? I might be able to make a change so as it is more to your liking. ### 2/5 — Hose size on the purge makes no difference *2021-01-07* Very disappointed to see that the purge time remains the same for a 15mm purge point as it does a 50mm Something very wrong here hey ### 2/5 — Seriously lacking *2020-09-27* This is fine for domestic and medium-sized commercial installations, but where it falls short is on calculations involving larger internal volumes. I find that once you get up to about 1.8 cubic meters or above, it simply errors and does not give purge and test times at all. Furthermore the steel pipe sizes (a) are given in mm when steel is always measured imperially - in inches and fractions (b) only goes up to 150mm - six inches - when eight inch, twelve and above are common. Disappointing app that really could be indispensable with these small changes. ### 2/5 — Wrong calculations *2019-11-14* Was a good app when I bought it until I realised the calculations were somehow wrong. I worked one out today using the book (did it three times) & came out as 191 second purge time where as this app said 94 seconds ! Be using the trusted book next time ! **Developer response:** Hi, could you please contact me at support@speaktothegeek.co.uk with your worked example so as I can reproduce the problem. Your assistance in resolving this will be greatly appreciated as current test scenarios are not showing any errors. ## Most praised reviews (7 highest-rated) ### 5/5 — Time saver *2016-03-16* Love this app as I do need the information on a day to day basis. Very accurate and saves time with calculations ### 5/5 — Commercial Gas *2015-06-29* At last a Commercial Gas App that works great , if you are in the Commercial gas game it's a must have App. ### 5/5 — Gas purge tool *2015-06-20* Great app. Using this app everyday, it is now an essential part of my tool kit. A must buy for every commercial gas engineer. ### 4/5 — Good helpful app *2017-08-16* Brilliant little app would be good to see a update so you can do over 1m3 at work to IGE/UP/1 And allow you to select new or existing installation. ### 3/5 — Could be better *2023-01-12* Would be a lot better and more useful if it was made useable for UP1 as well ### 2/5 — New or existing? *2017-11-02* This app would be great if it gave you the new or existing installation option. An update would be great. ### 2/5 — Fault with TTD *2015-08-18* Would have given this 5 stars but unless I'm missing something, there is a flaw within the total installation volume calculation. It doesn't add up when adding meter volume, pipe and fitting volume. Can't see how to contact developer regarding this to clarify, if this is fixed it would be great. --- *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 2026-09-04.*