Calculate the flat rectangular blank needed to develop a sheet metal cylinder, including circumference, surface area, volume and optional seam and trim allowances.
Seam allowance is added to the developed circumference. Trim allowance is added to the blank height. Set either value to zero when no allowance is required.
Enter cylinder dimensions and calculate.
What shape is a developed cylinder? A simple cylindrical shell develops into a rectangle.
How is cylinder flat length calculated? The theoretical flat length is the circumference, calculated as π × diameter.
What is the flat width? For a straight cylinder, the flat width corresponds to the cylinder height.
Why add a seam allowance? A seam allowance provides material for joining the two longitudinal edges by welding, riveting, lock seam or another process.
Does the calculator include end caps? No. It calculates the cylindrical shell. Circular end caps require separate blank calculations.
Can this calculate pipe or duct blanks? Yes, it can provide the basic rectangular development for a straight cylindrical shell.
Does thickness matter? The theoretical development is based on the diameter and height entered. For precision fabrication, confirm whether those dimensions refer to the inside, outside or neutral-axis diameter.
Can I use this for production? It is suitable as a preliminary development calculation. Production blanks should be checked against the actual joining method, tooling and dimensional convention.