Calculate your vehicle's top speed for each gear using transmission ratios, differential gear ratio, and rev limit. Optimize your car's gear ratio for track performance or drag racing, choosing between kmh and mph units.



116+ iOS apps curated and reviewed
If you already know Racing Diffs, this is the deeper bench. 116+ gear ratio apps for iPhone, all reviewed and ranked by user rating, recency, and download trend as of July 2026.
| # | App | Price | Rating | Ads | In-App Purchases | Updated |
|---|---|---|---|---|---|---|
| 1 | Free | 2.5★ (2) | No | No | May 2026 | |
| 2 | Free | 3.7★ (3) | No | No | May 2026 | |
| 3 | Free | 3.3★ (3) | No | No | May 2026 | |
| 4 | Free | 4.4★ (23) | No | Yes | Aug 2026 | |
| 5 | Free | 3.0★ (1) | No | Yes | May 2026 | |
| 6 | $0.99 | 3.8★ (120) | No | No | Aug 2026 | |
| 7 | Free | 5.0★ (1) | No | Yes | May 2026 | |
| 8 | Free | 1.0★ (1) | No | Yes | Aug 2026 |



Calculate your vehicle's top speed for each gear using transmission ratios, differential gear ratio, and rev limit. Optimize your car's gear ratio for track performance or drag racing, choosing between kmh and mph units.




Calculate essential dimensions for spur gears and pinions using diametral pitch or module. This tool provides outside diameter, center distance, and ratio for specific gear types.




This application simplifies driveline setup and predicts performance changes from gear ratios and tire size. It offers tools to calculate vehicle speed and RPM variables, aiding in rig planning and performance expectation.


This app offers a suite of specialized calculators for RC car enthusiasts. It helps with gear ratios, suspension geometry, corner weights, oil viscosity, fuel usage, and top speed estimations. It also stores data for multiple cars and includes helpful guides.


Calculate essential mountain bike gearing metrics like gear ratios, gear inches, and gain ratios. This tool helps cyclists understand and optimize their bike's performance.


This app is a powerful tool for RC car enthusiasts to calculate maximum speed and optimize gearing. It allows users to save setups, add notes, and email records for detailed tracking of performance. Supports a wide range of LiPo batteries and provides multiple calculation metrics.


This professional mechanical design tool helps engineers and enthusiasts calculate and optimize various gear parameters. It offers accurate calculations for different gear types, custom parameter input, and real-time design previews.


This application helps cyclists optimize their gear settings by calculating and visualizing gear ratios. It generates graphs for speed, cadence, and gear ratios based on various component combinations, aiding in the selection of replacement parts for improved performance.


Calculate and compare bicycle gear ratios to find the optimal gearing for your ride. Input chainring and cog sizes, and see detailed metrics like gear inches, speed, and more. Customize your setup or choose from presets for easy comparison.




This tool calculates gear ratios, torque, and speed for gear train systems. It allows users to simulate how these systems work on the fly, aiding in the design of custom gear systems before physical creation. Ideal for DIY enthusiasts and engineers.


Instantly analyze your bicycle's drivetrain performance. Calculate gear ratios, speed at any cadence, and climbing limits based on your bike's components and power output. Ideal for cyclists planning rides or optimizing their setup.


This app helps radio control car racers calculate their final drive ratio and rollout. Easily select your car, input gear sizes, and get instant results. It also offers charts and saves favorite cars for quick access.


This app helps track cyclists calculate gear ratios and speeds. It supports a wide range of chainring and cog sizes, and can determine optimal gear changes. Results can be displayed in Imperial or Metric units.


Optimize your bicycle's gearing with this comprehensive calculator. Analyze gear ratios, calculate speed at cadence, and manage custom configurations. Features include component browsing, sharing options, and helpful articles.


Calculate and visualize gear ratios for road bikes and MTBs. Simulate optimal gear combinations with various chainwheels, sprockets, and tires. Helps in selecting replacement parts by displaying speed-cadence graphs and gear ratio charts.


Calculate gear ratio, driveline ratio, and vehicle speed for various vehicles. Supports US and Metric units, with multiple input methods for tire size. Saves calculations for quick reference and allows emailing results.




This app provides essential calculators for off-road enthusiasts, focusing on gear ratios and other critical calculations. It brings popular web-based tools to your mobile device for easy access.


Calculate and compare transmission gear ratios with various tire and wheel sizes. Visualize results with interactive graphs and save them as PDFs. Includes calculators for gear speed, and both inch and millimeter tire sizes.