RC Pit Calc Pro: Gear Ratios

The RC gear ratio calculator trusted by racers and bashers — plus every other calculator you need at the track, in one free app.

GEAR RATIO CALCULATOR
Calculate gear ratio, final drive ratio (FDR), and rollout from your pinion and spur. Enter your gears "before and after" to see the real impact of gear and tire changes as a percentage (e.g. +2.5%), so you know exactly how much speed and motor load to expect. Built-in transmission data for hundreds of popular RC cars.

PINION RECOMMENDER
Not sure which pinion to run? Pick your car, enter your motor, and get a starting pinion from how racers in your class actually gear, plus the range they run. Built from real race setups across hundreds of classes.

TOP SPEED CALCULATOR
For electric cars with brushless motors: enter basic info about your setup and get a solid estimate of your car's top speed.

PILL INSERT / SUSPENSION GEOMETRY CALCULATOR
Find your toe, anti-squat, kick-up, roll center, and track width. Supports all popular cars that use pill inserts, and works with custom suspension mounts.

CORNER WEIGHT CALCULATOR
Enter your car's corner weights and get the full breakdown: front-rear, left-right, and cross weight/wedge.

SHOCK OIL TEMP & VISCOSITY CALCULATOR
Racing on a hotter or colder day than usual? See exactly what shock oil to run to keep the same car feel.

OIL BLENDING CALCULATOR
Don't have the right shock oil with you? Blend the thick and thin oils you already own — this calculator gives you the exact proportions for your target viscosity.

SHOCK DAMPING CALCULATOR
Compare two piston and oil combinations before you build the shock: roll damping, bump pack and jump pack side by side. Supports tapered pistons and dual hole sizes, with presets for common 1/10 and 1/8 shocks plus custom sizes.

FUEL USAGE CALCULATOR
For nitro racers: fuel burn per minute in race conditions, how much you need to finish long mains, and how many pit stops to plan.

FEATURES
- Remembers your entries for each car
- Built-in data (spur gear, transmission ratio) for hundreds of popular cars
- Walkthroughs and detailed help for every calculator

FROM SO DIALED
Want tuning help beyond the math? Our RC Setup App gives you pro setup sheets for 600+ cars, race logging, and an AI mechanic — find "RC Setup App" on Google Play.

Recent changes:
Fixed an issue that gave an incorrect anti-squat angle for some users.