# The OB Wheel Pro 7 — Gestational Age Calculator > Comprehensive prenatal care calculator for healthcare professionals and pregnant women. (iPhone/iPad app by Don Miller.) - Source: https://appshunter.io/ios/app/the-ob-wheel-pro-7/id730081554 (this page in markdown: same URL + `.md`) - Developer: [Don Miller](https://appshunter.io/developer/284593781) - Category: Medical, Health & Fitness - Price: $1.99 - Rating: 4.00/5 from 5 App Store ratings · 17 written reviews indexed - Age rating: 4+ - Requires: iOS 11.0 · 1 MB - Languages: American English, French (France), German (Germany), Italian, European Portuguese, European Spanish - Released: 2013-10-28 - Data updated: 2026-08-24 - Monetization: paid - User reviews in markdown: https://appshunter.io/ios/app/the-ob-wheel-pro-7/id730081554/reviews.md ## What is The OB Wheel Pro 7? The OB Wheel Pro 7 is the most complete, powerful, and easiest-to-use tool for healthcare professionals providing prenatal care. In just ONE app there is 1) a gestational age calculator, 2) an ultrasound biometric calculator, 3) a fetal weight calculator, 4) a list of key weeks and trimesters, 5) an age-adjusted risk table for trisomy 21 and aneuploidy, 6) a BMI calculator, and NOW 7) an Apple Watch app is included with your purchase! The OB Wheel Pro 7 is a state-of-the-art gestational age calculator (also known as an obstetric or pregnancy wheel) that is used every day by doctors, obstetricians, midwives, nurses, and pregnant women. The OB Wheel Pro 7 is a professional tool that replaces the need for multiple apps and it greatly enhances the functionality of those worn-out cardboard wheels without compromise. The OB Wheel Pro 7 accurately determines the estimated delivery date (EDD), or due date, of a pregnancy based on the first day of a woman's last menstrual period (LMP), or from the date of conception, or from a known gestational age (GA) on a known date, e.g. from an ultrasound measurement, or from fetal biometry like Crown-Rump Length (CRL), Femur Length (FL), and BiParietal Diameter (BPD). Additionally, for appropriate gestational ages, The The OB Wheel Pro 7 estimates fetal weight and displays the number of days completed and remaining. The OB Wheel Pro 7, besides calculating GA from fetal ultrasound biometrics, enables clinicians to also calculate Estimated Fetal Weight (EFW) from FL, BPD, Head Circumference (HC), and Abdominal Circumference (AC) using the most appropriate published reference formula using the maximum and most appropriate parameters. Prenatal care providers know that there are key gestational ages where testing or interventions are needed. The OB Wheel Pro 7 lets providers see at a glance when these items should be scheduled. FEATURES • Includes Apple Watch app! • Gestational Age Calculator from LMP, EDD, Conception Date for any reference date • Gestational Age calculated from specific date and gestational age (e.g. ultrasound) • Gestational Age Calculator using fetal biometrics (CRL, FL, BPD) • Fetal Weight Calculator using HC, AC, FL, BPD • Body Mass Index (BMI) Calculator • Age-Adjusted Risk Table for Trisomy 21 and aneuploidy • List of key completed weeks during pregnancy • Pregnancy days completed and remaining, and dates for each trimester • Remembers last-used EDD PRO TIPS: • To enter Gestational Age, CRL, FL, or BPD for a specific date (like for an ultrasound exam), tap "Today", enter the desired date, then tap on the button displaying the gestational age to change that button to display options for entering a specific GA, CRL, FL, and BPD. • When using the GA calculator, double-tap a date to change the value to the current date. • When using the EFW calculator, double-tap a value to clear the value of the selected parameter. ## Key features - Gestational Age Calculator - Ultrasound Biometric Calculator - Fetal Weight Calculator - Risk Table for Trisomy 21 - BMI Calculator - Apple Watch App ## Recent user reviews (10 of 17) All indexed reviews: https://appshunter.io/ios/app/the-ob-wheel-pro-7/id730081554/reviews.md ### 5/5 — Essencial na prática diária. *2025-01-05* Com um pouco de treino, extremamente intuitivo e rápido, definitivo para ajudar em atendimento obstétrico de urgência, ambulatorial, ultrassonografia, cardiotocografia. Meu aplicativo padrão de cálculo de idade gestacional, único que calcula com facilidade a IG em determinada data, com extrema precisão. Parabéns! ### 1/5 — Nao entrega o que promete *2024-04-30* Nao possui calculo da IG pelo USG! Nao consigo contato com a empresa para solucionar o problema! ### 1/5 — Muito ruim *2021-09-18* Não calcula pela 1ª ultrassom, mto complexo…um desperdício… ### 3/5 — App on the apple watch *2021-01-19* Good app on iphone, but the app did not work on the apple watch. And I buy this app to calculate due date on the go on my apple watch. ### 1/5 — Waste of money *2021-01-05* I work at an OB clinic and purchased this to use on my watch. It will not open. Complete waste of money. ### 4/5 — Doesnt open on apple watch *2020-10-06* I work as an RN in a womens health clinic and have been using this app during my time here. Its so easy to use and saves so much time when I chart expecting mothers. The only problem is that it seems it isn’t compatible with my watch anymore and when i try to open the app, all I see is a spinning wheel. Otherwise I loved this app when i was able to use it! ### 5/5 — Amazing *2019-03-31* I love your app and I use it everyday. Thank you. I was waiting for this update to use in my iPhone X. Maybe you could update the Apple Watch app too to take advantage of the big screen. Thank you. ### 5/5 — Good app *2019-03-31* Update.... not sorry for what I said three years ago, but sorry I never updated my review. It works great now and I use it all the time. **Developer response:** This review refers to a previous version before Apple allowed developers to even access the Digital Crown. After Apple allowed developer access to the Digital Crown, this app was updated to 2.0 in late 2015. As far as we can tell by looking at competitors' descriptions, The OB Wheel Pro 7 is the ONLY gestational age calculator that comes with an Apple Watch application. ### 4/5 — Keeps cutting out on Bmi screen *2018-12-05, version 2.0* Every time I try to work out a client’s BMI it keeps cutting out. Have tried installing it but still keeps happening. Please advise ### 1/5 — Incompleto e cheio de bugs *2017-09-29* Não permite cálculo de idade gestacional baseada na 1ª Ultrassonografia. Sempre dá Bug no cálculo de IMC quando a altura é superior a 180cm. ## Frequently asked questions about The OB Wheel Pro 7 ### What is the OB Wheel Pro 7? The OB Wheel Pro 7 is a medical application designed for prenatal care. It functions as a gestational age calculator, ultrasound biometric calculator, fetal weight calculator, and includes risk tables and a BMI calculator. ### How accurate is the OB Wheel Pro 7? The app accurately determines estimated delivery dates (EDD) based on the first day of the last menstrual period (LMP), conception date, or gestational age from ultrasound measurements. It also calculates fetal weight using appropriate reference formulas. ### What is the price of the OB Wheel Pro 7? The OB Wheel Pro 7 is available for a one-time purchase of $1.99. ### What devices does the OB Wheel Pro 7 support? The OB Wheel Pro 7 is supported on Apple Watch, iPhone, and iPod. It also includes a dedicated Apple Watch app. ### How often is the OB Wheel Pro 7 updated? The OB Wheel Pro 7 was last updated on March 30, 2019. Its latest version is 2.1. ### Does the OB Wheel Pro 7 have ads? No, the OB Wheel Pro 7 does not contain advertisements. It is a paid application. ### What are the key features of the OB Wheel Pro 7? Key features include a gestational age calculator from LMP or conception, calculation from ultrasound biometrics, fetal weight estimation, a BMI calculator, and an age-adjusted risk table for trisomy 21. ### What is the age rating for the OB Wheel Pro 7? The OB Wheel Pro 7 has an age rating of 4+, making it suitable for a wide range of users. ## Version history (last 5 releases) ### 2.1 — 2019-03-30 Now shows status display on top. Display now adapts to newer iPhones. Fixed crashes when calculating BMI when metric height and weight exceeded maximums. ### 2.0 — 2016-01-06 Completely new Apple Watch user-interface (WatchOS 2 required, WatchOS 1 no longer supported) Apple Watch app works without iPhone ### 1.3 — 2015-04-20 Now INCLUDES Apple Watch app! Now optimized for all iPhone devices. ### 1.2 — 2014-03-21 Display fix when date updated. Localization display fix in calculator. Added Portuguese localization. None of the bugs affected accuracy of calculations. ### 1.1 — 2013-11-29 Minor bug and display fixes. ## Apps similar to The OB Wheel Pro 7 | App | Rating | Price | Category | | --- | --- | --- | --- | | [Dog Symptom Checker](https://appshunter.io/ios/app/dog-symptom-checker/id392537780) | 1.0 (1) | $2.99 | Medical | | [Cardio Valve](https://appshunter.io/ios/app/cardio-valve/id516325480) | 4.8 (4) | Free | Medical | | [Hypnosis for Childbirth](https://appshunter.io/ios/app/hypnosis-for-childbirth/id477599840) | 5.0 (1) | $4.99 | Medical | | [AcuApp® Acupressure](https://appshunter.io/ios/app/acuapp-acupressure/id510935540) | 3.5 (2) | Free | Medical | | [ICE Medical Standard](https://appshunter.io/ios/app/ice-medical-standard/id412786820) | 4.3 (1,951) | Free | Medical | | [CCL eLab Community](https://appshunter.io/ios/app/ccl-elab-community/id492766180) | — | Free | Medical | ## More apps by Don Miller - [colorCal+ Calendar](https://appshunter.io/ios/app/colorcal-plus-calendar/id354898697) - [Podium Timer Pro](https://appshunter.io/ios/app/podium-timer-pro/id897941871) - [The Fab Four](https://appshunter.io/ios/app/the-fab-four/id1227940026) - [2021 CDC STI (STD) Guidelines](https://appshunter.io/ios/app/2021-cdc-sti-std-guidelines/id1618309189) All apps by Don Miller: https://appshunter.io/developer/284593781 ## Related topics [the ob wheel pro 7](https://appshunter.io/ios/topics/the-ob-wheel-pro-7) · [gestational wheel](https://appshunter.io/ios/topics/gestational-wheel) · [ob wheel due date calculator](https://appshunter.io/ios/topics/ob-wheel-due-date-calculator) --- *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 2026-08-24.*