Grip Dial's Gear Ratio Calculator
Grip Dial – Gear Ratio Calculator
Tire Size
Diameter
Metric Size
P-Metric Tire Size (e.g. 275/35R18)
Calculated: 25.6" diameter
Final Drive
Transmission Ratios
Engine
Drag Racing Calculator
Find Ideal Final Drive Ratio
Ideal Final Drive Ratio
4.11:1
Speed & RPM by Gear
| Gear | Ratio | Overall | Speed @ Redline | RPM @ 60 mph | RPM Drop |
|---|
Performance Summary
Speed vs RPM Chart
How to Use
Formula: MPH = (RPM × Tire Diameter) ÷ (Gear Ratio × Final Drive × 336)
Tire Size: Enter diameter directly or use metric calculator (e.g., 275/35R18).
Transmission Presets: Click to load common transmission ratios. Set unused gears to 0.
RPM Drop: Shows RPM decrease when shifting to the next gear at shift RPM.
Drag Calculator: Enter your target trap speed and finish line RPM to find the ideal rear gear ratio.
Tire Size: Enter diameter directly or use metric calculator (e.g., 275/35R18).
Transmission Presets: Click to load common transmission ratios. Set unused gears to 0.
RPM Drop: Shows RPM decrease when shifting to the next gear at shift RPM.
Drag Calculator: Enter your target trap speed and finish line RPM to find the ideal rear gear ratio.