# Gear Formula: Calc & Simulator — Gear Ratio, RPM & Torque Tools

> Gear Ratio, RPM & Torque Tools (iPhone/iPad app by Le Minh Tran.)

- Source: https://appshunter.io/ios/app/gear-formula-calc-and-simulator/id6786232651 (this page in markdown: same URL + `.md`)
- Developer: [Le Minh Tran](https://appshunter.io/developer/1896777000)
- Category: Utilities, Education
- Price: Free with in-app purchases
- Age rating: 4+
- Requires: iOS 15.0 · 34 MB
- Languages: American English
- Released: 2026-07-13
- Data updated: 2026-07-20
- User reviews in markdown: https://appshunter.io/ios/app/gear-formula-calc-and-simulator/id6786232651/reviews.md

## What is Gear Formula?

Gear Formula: Calc & Simulator is a visual gear calculator and simulator for real-world transmission planning, learning, and quick design exploration.

Built for bicycle riders, RC car builders, robotics teams, automotive tinkerers, mechanical engineering learners, DIY gearbox makers, and education use cases, the app helps you understand how gear choices affect ratio, speed, torque, and motion.

What you can do:
- Explore different gear families with clear visual selection flows.
- Calculate gear ratio, RPM change, torque change, and drivetrain behavior.
- Edit transmission values and see the simulator update in real time.
- Compare how tooth counts and key parameters change the result.
- Use guided validation feedback to review whether a setup looks balanced or too extreme.
- Save and revisit useful configurations with Pro features.
- Share saved configurations through app links with Pro features.

Supported gear families in the current app:
- Chain and sprocket
- Spur gear pair
- Planetary gear set
- Bevel gear pair
- Worm drive
- Rack and pinion
- Compound train

Designed for multiple audiences:
- Bicycle
- RC Car
- Robotics
- Automotive
- Mechanical Engineering
- DIY Gearbox
- Education

Why Gear Formula is useful:
- It is faster than doing repeated ratio math by hand.
- It makes gear behavior easier to understand visually.
- It helps users move from “What does this gear setup do?” to “Is this setup good for my goal?”
- It works well for quick mobile checking, concept exploration, and learning.

Important:
Gear Formula is a reference and educational tool. Calculations, simulations, and validation guidance are not a substitute for professional engineering review, safety testing, or manufacturing verification.

Free and Pro:
The free version supports core calculation and simulation.
Pro unlocks advanced workflow features such as Save, Share, Bookmark, and Validate, and also removes ads.

Whether you are tuning cadence, exploring gearbox reduction, teaching gear fundamentals, or testing drivetrain ideas on the go, Gear Formula gives you a practical mobile workspace for gear calculation and simulation!

## Pricing and in-app purchases

Base price: Free.

**One-time purchases**

| Purchase | Price | Type |
| --- | --- | --- |
| Remove Ads | $1.99 | one-time |
| Unlock Pro Features | $2.99 | one-time |



## Version history (last 1 release)

### 1.0 — 2026-07-13

No release notes.

## More apps by Le Minh Tran

- [Inductor Calculator Master](https://appshunter.io/ios/app/inductor-calculator-master/id6772124135)
- [Resin Calculator Master](https://appshunter.io/ios/app/resin-calculator-master/id6772931749)
- [Wood Project Calculator](https://appshunter.io/ios/app/wood-project-calculator/id6775448936)
- [Balltacus - Ball Arena](https://appshunter.io/ios/app/balltacus-ball-arena/id6779310217)

All apps by Le Minh Tran: https://appshunter.io/developer/1896777000

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*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 2026-07-20.*