01
Gear Speed
Calculate theoretical vehicle speed from engine RPM, tire size, final drive and each gear ratio, including redline speed, wheel RPM and total ratio.
Offline · Paid once · No account
Drivetrain math for real builds.
Gear Ratio Calculator RPM helps car, motorcycle, RC and drivetrain users calculate speed, RPM, final drive, tire changes and setup comparisons offline, then save results by project.
Core Features
02
Speed Curves
Visualize how each gear behaves across an RPM range for shift planning and cruising analysis.
03
Tire Compare
Compare original and replacement tires for diameter, circumference, speedometer error and cruising RPM change.
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Project Library
Keep reusable setups, calculation records and exported report history grouped by vehicle or build.
05
Setup Compare
Select saved setups to compare cruise RPM, redline speeds and key drivetrain differences.
06
Local Export
Create PDF, CSV, PNG and JSON files for archiving, sharing or backup.
Built for paid offline use.
The app does not rely on a server and does not include ads, subscriptions or accounts. Calculations and project data stay on device by default, with user-controlled file export.