RC hobbies calculators

Enter the airplane weight, measured CG, target CG, and the station where ballast can be mounted. The calculator solves the aircraft moment equation backward and shows the added weight, final flying weight, and corrected CG check.

Enter the wing, tail moment arms, existing tail areas, and target tail-volume coefficients. The calculator checks the current coefficients and reverse-solves buildable tapered tail dimensions.

Enter the ready-to-fly weight, wing area, CLmax, and field conditions to estimate wing loading and stall speed. The target stall speed also reverse-solves the maximum weight that would meet that speed.

Estimate how long one LiPo pack should run when your RC car alternates between hard and easy driving. The calculator also estimates the capacity and number of packs needed for a planned session, while keeping a reserve in the pack.

Enter two silicone oil viscosities to solve a target cSt blend, or enter a known percentage to predict the finished viscosity. The result gives scale-ready gram amounts plus approximate milliliters from the densities you enter.

Enter the spur, pinion, internal ratio, tire diameter, and motor numbers to analyze a current RC car setup or solve for a target rollout or speed. The calculator compares available whole-tooth pinions instead of stopping at the algebraic answer.

Enter the motor, battery, gear, and rotor numbers to estimate current head speed and solve for the pinion that best fits a governed target. The result also checks governor headroom, full-charge ceiling, and blade-tip speed.

Enter the servo arm, control horn, pivot spacing, neutral angles, and servo endpoint travel. The calculator solves the planar linkage to estimate both control throws, differential, pushrod length, and the servo travel needed for a target surface angle.

Enter a matching pinion and spur pair to check its standard center distance and diameters. Or enter a fixed motor-to-spur shaft distance to find the nearest usable whole-tooth pinion.