Calculate Engine Displacement

This program calculates the displacement of motorcycle engine. The engine displacement is calculated in Cubic Inches or CC's. Enter the bore and stroke of the engine, the number of cylinders and select the measurement system the values are entered in. Then click the "Calculate" Button to display the answers. Pressing the "Reset" button loads the default values into the form.

If you prefer to do it yourself then here are the formulas:

Bore(mm)^2*Stroke(mm)*0.0031416/4
bore diameter x bore diameter x .7854 x stroke length x number of cylinders = displacement

For converting cc's to cubic inches, the formula is
cc / 16.387 = cubic inches

Formula for computing horsepower:
Torque x rpm / 5252 = horsepower

For computing torque when horsepower and rpm's are known:
Horsepower x 5252 / rpm = torque

Code from nightrider.com