Tank Services › Capacity

Tank Capacity Calculator

Calculate total and partial fill capacity for cylindrical (vertical/horizontal), rectangular and oval tanks in litres, m³ and US gallons.

Tank Capacity Calculator

Enter tank dimensions to calculate capacity.

Oval uses elliptical cross-section formula: π × (L/2) × (W/2) × height. For horizontal cylinders, diameter × diameter × length formula gives full barrel capacity.

Frequently Asked Questions

How accurate is this calculator?

Results are based on ideal geometric shapes. Real tanks may have rounded corners, domed ends or internal baffles that reduce usable volume by 2–5%.

What is the difference between gross and usable capacity?

Gross capacity is the full geometric volume. Usable (net) capacity is typically 90–95% of gross, accounting for the space below the outlet, above the overflow, and sump volume.

How many litres in a cubic metre?

1 m³ = 1,000 litres exactly. 1 US gallon = 3.785 litres; 1 Imperial gallon = 4.546 litres.

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