🧮 RC Calculators & Tools

Every calc a racer or basher needs — gearing, speed, LiPo, motor and prop. Live, mobile, free, no signup. Change a number, get the answer instantly.

⚙️ Gear Ratio & Rollout

Final drive ratio and rollout (how far the car rolls per motor turn) — the number racers actually tune by.

Final drive ratio
Rollout (mm)
Primary (spur÷pinion)

Lower FDR = more top speed but hotter motor/ESC. Higher FDR = more punch & cooler. Internal ratio is printed in your chassis manual.

🏎️ Top Speed

Theoretical top speed from motor KV, battery, gearing and tire size.

Real ~mph
Real ~km/h
Theoretical mph

"Real" applies ~85% for efficiency, voltage sag and drag. Actual speed varies with traction, weight and tire growth.

🔋 LiPo Pack & Runtime

Pack voltages, energy, max safe current and runtime — plus a C-rating check.

Runtime (min)
Max current (A)
Energy (Wh)
Nominal / Full V

🌀 Motor KV → RPM

No-load and loaded motor RPM from KV and pack voltage.

No-load RPM
Loaded ~RPM

KV = RPM per volt. Loaded uses ~80% for a typical geared load.

✈️ Prop Pitch Speed (planes)

Theoretical max airspeed a prop can deliver at a given RPM.

Real ~mph
Real ~km/h
Pitch speed mph

Real airspeed is ~85% of pitch speed after prop slip.

More tools coming — setup-sheet builder, shock-oil converter, corner-weight and thrust calc. Join the crew to save your rigs and get AI setup help.