# Planetary Gear Calculator — Design Planetary Gears System > Calculate and simulate planetary gear systems for design and engineering. (iPhone/iPad app by Heng Jia Liang.) - Source: https://appshunter.io/ios/app/planetary-gear-calculator/id1618146516 (this page in markdown: same URL + `.md`) - Developer: [Heng Jia Liang](https://appshunter.io/developer/1532000635) - Category: Productivity, Utilities - Price: $3.99 - Rating: 4.70/5 from 6 App Store ratings · 2 written reviews indexed - Age rating: 4+ - Requires: iOS 13 · 1 MB - Languages: American English - Released: 2022-04-07 - Data updated: 2026-08-13 - Monetization: paid - User reviews in markdown: https://appshunter.io/ios/app/planetary-gear-calculator/id1618146516/reviews.md ## What is Planetary Gear Calculator? Planetary Gears Calculator calculate the gear teeth and gear speed of planetary gears system. Plus quickly simulate how the Planetary Gears works on the fly. This is a great tool, especially for DIYer who want to design their own Planetary Gears System quick and easy. Preview how these systems work before 3D print own planetary gear system. Formula for Planetary gear systems: Sun Teeth = ringTeeth - 2 * planetTeeth Planet Teeth = (ringTeeth - sunTeeth) / 2 Ring Teeth = sunTeeth + 2 * planetTeeth ST = sunTeeth PT = planetTeeth RT = ringTeeth SunSpeed = (ST+RT)/ST * PlanetCarrierSpeed - RT/ST * RingSpeed PlanetCarrierSpeed = RT/(ST+RT) * RingSpeed + ST/(ST+RT) * SunSpeed RingSpeed = (ST+RT)/RT * PlanetCarrierSpeed - ST/RT * SunSpeed Planetary gear systems, also known as epicyclic gear systems, are important components in modern engineering. Planetary gear systems are useful for speed variation and commonly found from automatic car transmissions and industrial food mixers to operating tables and solar arrays. There are four core components that make up the planetary gear systems, the ring gear, the sun gear and the planetary gears connected to the carrier. Thanks for your support and do visit nitrio.com for more apps for your iOS devices. ## Key features - Calculate gear teeth - Calculate gear speed - Simulate planetary gear systems - Design custom gear systems - Preview system functionality - Understand gear formulas ## Recent user reviews (2 of 2) All indexed reviews: https://appshunter.io/ios/app/planetary-gear-calculator/id1618146516/reviews.md ### 5/5 — Gears can’t be noted with negative ’s *2024-06-27* This gear is losing atomic structure and will collapse like before we expanded and noted it correctly with the math. If you code using a minus or possibility of one then this is poor code. Never ask for nothing. Expect something, every second, penny, ray, light , sound and mirror moment counts and has substance. Use an ~> arrow instead of a - or if logic still allows negatives then go through these simple proofs 1 +is always positive, where one goes it will always equal one. One degree, one person, one atom etc if moved will be 1 when it arrives whether in accounts receivable, accounts payable or below zero degrees, 108 becomes 109 when it arrives but how could 109 lose one if 1 is moved of course. Math books show minus but shops, suns, humans and wolves know that it’s not the computers fault we didn’t book very well, killed trillions of semis and all of the sky but in real life there isn’t a minus only a move. Even nothing doesn’t go below zero because there he doesn’t exist and neither do instructions, life or love, below zero some things are noted because they get cold there but those are degrees and not accounting. They are permanent markers that could have been done better if anyone knew how cold it could be but we didn’t. The fact we fix this and below sea level should tell you how destructive to health, growth, money or friends subtracting or dividing yourself can be. When others do it try to correct them until all are sick of it then repeat. It is too important. In 3 days the Sun would break because the nicest lady has a bad code. The depression would be felt around the Universe! Don’t be a breaker be a light that shines always as you were intended to be! ### 1/5 — Mr *2024-05-25* App doesnt work well. ## Frequently asked questions about Planetary Gear Calculator ### What is Planetary Gear Calculator used for? Planetary Gear Calculator is used to calculate the gear teeth and gear speed of planetary gear systems. It also allows users to quickly simulate how these systems work on the fly, aiding in the design process. ### Who would benefit from using Planetary Gear Calculator? This app is particularly useful for DIYers who want to design their own planetary gear systems quickly and easily. Engineers and hobbyists involved in mechanical design will also find it valuable. ### Does Planetary Gear Calculator offer a free trial? Planetary Gear Calculator is a paid app priced at $3.99. There is no mention of a free trial period in the provided data. ### What devices is Planetary Gear Calculator compatible with? Planetary Gear Calculator is compatible with iPhone, iPad, and iPod devices. It is designed for iOS platforms. ### How often is Planetary Gear Calculator updated? The app was last updated on January 23, 2026, with version 1.1 released. This indicates a recent update, suggesting ongoing support and development. ### What is the age rating for Planetary Gear Calculator? Planetary Gear Calculator has an age rating of 4+. This means it is suitable for users aged 4 and above. ### Does Planetary Gear Calculator have ads? No, Planetary Gear Calculator does not contain advertisements. The app is ad-free, providing an uninterrupted user experience. ### What are the core components of a planetary gear system according to the app? The app describes the four core components of a planetary gear system as the ring gear, the sun gear, the planetary gears, and the carrier. ## Version history (last 2 releases) ### 1.1 — 2026-01-23 - Updated for the newest devices. - Minor bugs fixed. ### 1.0 — 2022-04-07 No release notes. ## More apps by Heng Jia Liang - [Time Lapse Plus](https://appshunter.io/ios/app/time-lapse-plus/id806506963) - [Stop Motion Plus](https://appshunter.io/ios/app/stop-motion-plus/id815531972) - [Bubble Photo Paint](https://appshunter.io/ios/app/bubble-photo-paint/id921345975) - [Photo Art Painter](https://appshunter.io/ios/app/photo-art-painter/id1037774115) - [Batch Image Resize](https://appshunter.io/ios/app/batch-image-resize/id1117282560) - [Dash Cam Plus](https://appshunter.io/ios/app/dash-cam-plus/id1130785852) All apps by Heng Jia Liang: https://appshunter.io/developer/1532000635 ## Related topics [planetary gear calculator](https://appshunter.io/ios/topics/planetary-gear-calculator) · [gear ratio calculator lite](https://appshunter.io/ios/topics/gear-ratio-calculator-lite) --- *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 2026-08-13.*