Get our free calculator app, so it's always handy!
Gear Ratio Calculator
Use our gear ratio and rollout calculator to find the right pinion and spur for your car, whether it's Team Associated, Tamiya, Traxxas, or any other make, . Enter your car's internal drive ratio to see the final drive ratio (FDR), and see the percentage change in gearing you'll get from a new pinion and spur.
Gears & Ratios
Enter your gearing to see the how your ratio will change.
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Negative changes indicate a steeper ratio: higher top speed, but more strain on the motor/engine. Positive changes give more acceleration and put less strain on the motor/engine.
5 Stars on the App Store
Ian C.
Something every racer should have
Cody B.
Helped me get a perfect top out speed and keep good temps.
William W.
This is app is a big hepl to me to actually know and see what my drag car is doing very useful app, highly recommend it to anyone who drag race.
Cole M.
Great little tool, get their other app to called "SO DIALED" its a lifesaver for tuning!
Heath M.
It has changed me as a human, made me care a little more about humanity and the fellow creatures on this Earth. It's also a great R/C gear calculator.