Get our free calculator app, so it's always handy, or try our new Gear Recommender App!

So Dialed RC Setup App on the App StoreSo Dialed RC Setup App on the App Store

5 Stars on the App Store

Joseph O.
Great to have a quick calculator on hand when at the track. Nice to have a compare feature to see current and new gear change calculation.
Ian C.
Something every racer should have
Zaulu B.
Good app - it really lets you see what you are doing when pairing your gears. I would recommend it for anybody trying to hit high speed.
Cody B.
Helped me get a perfect top out speed and keep good temps.
Michael D.
Life saver...awesome app that helps tremendously.
William W.
This app is a big help to me to actually know and see what my drag car is doing. Very useful app, highly recommend it to anyone who drag races.
Billy J
This app is so helpful. It's a great tool to get your RC where you would like it to be.
Louis M.
Very easy and intuitive to use. It has been really helpful pairing different spur and pinion gears. No guessing or calculations needed. 0 % or 10 percent change, or whatever change, it shows you.
Cole M.
Great little tool, get their other app too, called "SO DIALED." It's a lifesaver for tuning!
Jonathan H.
Excellent tool to manage your desired FDR. I use it on my touring car and my 1/12 pan car.
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.
Bryan T.
Excellent app for all tuning needs
Jason R.
Easy to use, and convenient!

Online Gear Ratio Calculator

Looking for a quick gear calculation, so you don't have to download an app? Try 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.
Ratio
1
1
Ratio change
0%
Internal ratio
(Optional)
FDR
1
1
Rear tire diameter (Optional, for rollout)
Rollout
Thank you! Your submission has been received!
Oops! Something went wrong while submitting the form.
Get our free Gear Calculator App (links above),
or try our
Gear Recommender App!

Change Impact Chart

Click/tap the gears to see how new gears will affect your ratio:
Pinion
Spur
13
0%
74
0%
14
0%
75
0%
15
0%
76
0%
16
0%
77
0%
17
0%
78
0%
18
0%
79
0%
19
0%
80
0%
20
0%
81
0%
21
0%
82
0%

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.