01 / Select Profile
Choose your tank shape
The calculation model changes automatically with the selected cross-section.
2D Profile Preview
Live geometry based on your dimensions
Visualization is a proportional engineering illustration. It is not a fabrication drawing.
02 / Enter Dimensions
Spell Cylinder
Enter the overall width, height and straight shell length.
03 / Fill Calculation
Calculate filled volume
95% of the profile height = 0 mm until dimensions are entered.
Reports the entered volume, capped at the calculated capacity.
Dish-end volume is an engineering estimate: V = 2 × ⅔ × A × E. Actual volume depends on crown and knuckle radii.
Enter valid dimensions to calculate capacity.
04 / Advanced
Geometry, sizing and fabrication estimate
Optional controls. The main calculator updates automatically.
Spell profile geometry
Edit the central rectangle. The four circular arcs are derived from the overall and rectangle dimensions.
These scale automatically with your overall width and height until you type your own values. The 140 mm corner fillet deduction is fixed. Rw must not exceed the overall width and Rh must not exceed the overall height.
Active: 140 mm (default).
Calculate a dimension from known volume
Enter a target capacity and choose which variable to solve.
Uses the entered fixed dimensions and the embossed-end setting. Width and height use a numerical search.
Baffle plate / compartment estimate
Sections are sized on a usable volume. A new baffle is added only when a section would exceed its allowed maximum.
Max section = S × (1 + k) — 6,000 L
Percent of capacity used to size sections.
Actual compartment design, openings and statutory requirements must be confirmed by an engineer.
Material and estimated fabrication weight
Weight estimation is password protected. Enter the access password to unlock it.
Shell defaults to 3 mm; dish ends and baffle plates to 4 mm.
Leave blank for steel weight only. Liquid mass = filled volume × density.
Estimates only. Steel = shell + two dish ends + baffles. Fittings, manholes, brackets, valves, welds and chassis are not included.
Dish curvature, welds, supports, fittings, cut-outs and overlaps are excluded.
Circumference & corner marking calculator
Estimate the developed sheet length for roll bending. Spell profiles include corner-marking positions; circle and oval profiles do not use these four corner marks.
Sheet length estimate = profile perimeter + π × thickness + extra allowance. Confirm the neutral-axis factor, seam/weld allowance and shop roll-bending method with your fabricator.