Instructions

• Tire diameter — enter the outer diameter in inches. This directly affects speed calculation.
• Final drive — the rear axle ratio (e.g., 3.73). Higher number = shorter gearing.
• Max RPM — the maximum engine speed used for the table.
• Converter slip % — torque converter slip percentage. Adds realism for automatics.
• Quick Change — Winters-style rear. If “Yes”, enter high/low gear teeth. Their ratio is included in overall gearing.
• Number of gears — choose gear count and enter each ratio. A preset can auto-fill these but fields remain editable.

What the tool shows

• Speed table — per-gear speed at RPM increments (km/h and mph).
• Overall ratio — header shows gear ratio and then [overall X.XX] = gear × Quick Change × diff.
• Gauges — pick a gear and move RPM slider to see real-time speed.

You can use this tool to estimate:

• How speed changes with different final drives or tires.
• Speed at a given RPM in each gear.
• Quick Change gear impact on overall gearing.
• Converter slip effect on actual speed.