Capacity Suite Calculator

Capacity is a practical reference calculator for pressure vessel heads and cylindrical shells. Enter the component dimensions and material density to quickly calculate capacity, volume, empty weight, surface area, and flow area.

Supported components:
• 2:1 ellipsoidal head
• 6% flanged and dished head
• 10% flanged and dished head
• 17% flanged and dished head
• Cylindrical shell

Enter the inner diameter, wall thickness, straight flange or cylinder length, and material density. Capacity then provides:
• Internal capacity
• Total volume
• Metal volume
• Empty weight based on material density
• Inside surface area
• Outside surface area
• Flow area

Choose the units that fit your workflow:
• Capacity and volume: L, m³, US gal, Imp gal, bbl, and ft³
• Area: m², ft², mm², and in²
• Weight: t, kg, and lb

Save and reuse your results:
• Copy input values and calculation results as text
• Save a clean result card as a PNG image
• Keep preferred units, precision, and display settings for your next calculation

Calculation inputs are processed locally on your device and are not uploaded to a calculation server. The calculation itself does not depend on a network connection.

Capacity is designed for quick reference, estimation, and comparison. Each calculation represents one open vessel component. Flat end plates, additional heads, nozzles, and other attached components are not included.

Important:
This app does not calculate pressure, stress, allowable material limits, weld efficiency, corrosion allowance, fatigue, manufacturing tolerance, or code compliance. Results do not replace official design calculations, applicable codes and standards, manufacturer data, drawings, inspections, or review by a qualified engineer