This simple Gearhead Light app is the free version that calculates engine compression ratio, speed, RPM, tire size, etc. There are still no ads or special phone access.

If you are a hobby gearhead, you’ll want Gearhead Light! Gearhead Light is the free calculator app that us gearheads use for performance automotive parameters. It calculates engine, gearing & tire parameters. Gearhead Light works in both standard and metric units so you can select the most compatible parts for your application.

Gearhead Light calculates or estimates:

- Engine RPM from vehicle speed, gearing, tire size
- Vehicle Speed from engine RPM, gearing, tire size
- Tire Diameter and Cross section width from sidewall size
- Simple gear ratios based on drive and driven tooth count

- Displacement from cylinders, bore, and stroke
- Bore/Stroke ratio
- Static Compression Ratio
- Compression Height (piston wrist pin height)
- Head gasket volume (from bore and compressed thickness if round)

If you are looking for more please check out our paid “Gearhead" apps.
None of our apps have ads or use invasive phone permissions

App Privacy

The developer, Innovate Engineering LLC, has not provided details about its privacy practices and handling of data to Apple. For more information, see the developer’s privacy policy.

No Details Provided

The developer will be required to provide privacy details when they submit their next app update.


  • Family Sharing

    Up to six family members will be able to use this app with Family Sharing enabled.

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