Enter Tank Details
Use the responsive grid below. Large screens show three columns, medium screens show two, and mobile screens show one.
Example Data Table
| Tank Type | Example Dimensions | Fill Depth | Total Capacity (L) | Liquid Volume (L) |
|---|---|---|---|---|
| Vertical Cylinder | D = 2.2 m, H = 5.5 m | 4.1 m | 20,907.30 | 15,585.44 |
| Horizontal Cylinder | D = 1.8 m, L = 6.0 m | 1.1 m | 15,268.14 | 9,776.16 |
| Rectangular Tank | L = 4.0 m, W = 2.5 m, H = 2.0 m | 1.4 m | 20,000.00 | 14,000.00 |
| Spherical Tank | D = 3.0 m | 1.6 m | 14,137.17 | 7,774.39 |
Formula Used
The calculator converts all inputs to metres, calculates geometric volume in cubic metres, then converts the final result to the selected output unit.
Vertical cylinder: V = πr²h Horizontal cylinder at depth h: V = L[r² arccos((r-h)/r) - (r-h)√(2rh-h²)] Rectangular tank: V = L × W × h Spherical tank segment: V = πh²(3r-h)/3 Vertical capsule tank: bottom hemisphere segment + straight cylinder + top hemisphere segment Usable capacity = volume at (overall height - freeboard) Liquid mass = liquid volume (m³) × density (kg/m³)For horizontal cylinders, spheres, and capsule tanks, volume does not rise linearly with level. That is why the graph is helpful for calibration, operations, and level-to-volume conversion work.
How to Use This Calculator
- Select the tank geometry that matches your vessel.
- Choose the input length unit and desired output volume unit.
- Enter the required dimensions for that geometry.
- Enter current fill depth and any freeboard allowance.
- Optionally set density to estimate the liquid mass.
- Submit the form to see total, usable, and current liquid volume.
- Review the chart for depth-versus-volume behaviour.
- Use the CSV or PDF buttons to save your results.
Frequently Asked Questions
1. What is the difference between total and usable capacity?
Total capacity is the full geometric volume. Usable capacity subtracts the freeboard allowance, which reserves empty depth for expansion, foam, sloshing, or operating safety.
2. Why does a horizontal tank not fill linearly?
The wetted cross-sectional area changes with depth. Near the bottom and top, small level changes can create smaller or larger volume changes than they do near the midline.
3. Can I use this for fuel, water, or chemicals?
Yes, for planning and estimation. Enter the correct dimensions and density. For hazardous or regulated service, confirm dimensions, calibration, and material compatibility before final decisions.
4. Does freeboard reduce total tank size?
No. Freeboard does not change the tank’s actual geometry. It only reduces the recommended maximum operating volume by keeping some shell height intentionally empty.
5. Why is density entered in kg/m³?
The calculator computes volume internally in cubic metres. Using density in kg/m³ makes mass estimation direct and avoids hidden conversion errors in the liquid weight calculation.
6. Can this calculator replace field calibration tables?
It is excellent for engineering estimates and quick checks. Field calibration remains better when tanks include nozzles, internals, deformations, tilt, or fabrication tolerances.
7. What units are supported?
Input lengths can be entered in millimetres, centimetres, metres, inches, or feet. Results can be shown in litres, cubic metres, cubic feet, US gallons, or UK gallons.
8. When should I verify results manually?
Verify manually before procurement, fabrication release, custody transfer, or safety-critical operation. Independent checks are also wise when dimensions were taken from sketches or incomplete drawings.