Engine & drivetrain calculators
Choose a tool, enter your numbers, and follow the calculation.
Engine Displacement Calculator
Calculate engine swept volume in liters, cubic centimeters, and cubic inches from bore and stroke.
Engine & drivetrainHorsepower & Torque Calculator
Calculate horsepower from torque or torque from power at a given RPM. Supports lb-ft, N·m, mechanical hp, kW, and metric PS.
Engine & drivetrainGear Ratio RPM Calculator
Calculate engine RPM from mph or km/h, tire diameter in inches or millimeters, transmission gear, and final drive ratio.
Engine & drivetrainCompression Ratio Calculator
Calculate static engine compression ratio from bore, stroke and total clearance volume per cylinder, with metric or inch dimensions.
Engine & drivetrainMean Piston Speed Calculator
Calculate mean piston speed in meters per second and feet per minute from engine RPM and stroke in millimeters or inches.
Engine & drivetrainRod-to-Stroke Ratio Calculator
Calculate connecting-rod length divided by crankshaft stroke in millimeters or inches. Distinguish rod-to-stroke from rod-to-crank-radius ratio.
Engine & drivetrainEngine Airflow Calculator
Estimate four-stroke engine airflow in CFM and liters per minute from displacement, RPM and entered volumetric efficiency. Includes metric and cubic-inch inputs.
Engine & drivetrainAerodynamic Drag Power Calculator
Calculate a vehicle’s aerodynamic drag force and power in still air from speed, drag coefficient, frontal area and air density. See newtons, kW and hp.
Engine & drivetrainHill-Climbing Power Calculator
Estimate the extra mechanical power needed to lift a vehicle uphill at steady speed. Enter loaded mass, road grade or angle, and speed in mph or km/h.
Engine & drivetrainVehicle Elevation Energy Calculator
Calculate the mechanical energy needed to raise a loaded vehicle through an elevation gain. Convert kilograms or pounds and meters or feet to kWh, Wh and kJ.
Engine & drivetrainPower-to-Weight Ratio Calculator
Calculate vehicle power-to-weight ratio in hp per metric tonne, kW per tonne, lb per hp and kg per kW. Supports mechanical hp, metric PS and kW inputs.
Engine & drivetrainBMEP Calculator
Calculate brake mean effective pressure from crankshaft torque and total engine displacement. Compare two- and four-stroke engines in bar, kPa and psi.
Engine & drivetrainInjector Duty Cycle Calculator
Calculate injector duty cycle from pulse width, RPM and the pulse interval for one injector. See repeat period, pulse frequency and remaining off-time.
Engine & drivetrainBSFC Calculator
Calculate brake specific fuel consumption from fuel mass flow and engine brake power. Get results in g/kWh and lb/(hp·h), with metric and imperial inputs.
Engine & drivetrainVehicle Kinetic Energy Calculator
Calculate a car’s translational kinetic energy from mass and speed, plus the energy change when speeding up or slowing down. Results in kJ and Wh.
Engine & drivetrainVehicle Acceleration Calculator
Calculate average vehicle acceleration or deceleration from two speeds and elapsed time. Convert mph, km/h or m/s into m/s² and g.
Engine & drivetrainWheel Torque to Force Calculator
Calculate ideal drive force from wheel torque and effective rolling radius. Compare tire-radius scenarios with clear per-wheel and total-torque guidance.
Engine & drivetrainBrake Thermal Efficiency Calculator
Calculate engine brake thermal efficiency from BSFC and fuel lower heating value. See the energy balance per kWh of crankshaft output, with worked examples.
Engine & drivetrainEngine Mechanical Efficiency Calculator
Calculate engine mechanical efficiency from indicated and brake power in kW or hp. Find the power difference, with matched-measurement guidance and examples.
How to calculate engine clearance volume: chamber, gasket, deck and piston contributions.
How to read a dyno chart: matched RPM, graph scales and measurement boundaries.