Does this calculate usable capacity or total volume?

Total geometric volume. Subtract a safety margin for headspace, fittings, or fill limits to get practical working capacity.

Can I use this for a horizontal cylindrical tank?

The volume math is the same regardless of orientation. Just make sure you're entering the correct height/diameter relative to how the tank actually sits.

What if my tank has rounded (dished) ends instead of flat ends?

This calculator assumes flat ends. Dished or elliptical heads add a bit more volume that isn't captured here.

Tank & Vessel Volume Calculator

Find the holding capacity of a cylindrical or rectangular tank in gallons, cubic feet, and liters.

1. Tank Specifications

Tank Geometry Type

Input Measurement Unit

Internal Diameter

Vessel Straight Height

Internal Length

Internal Width

Vessel Depth / Height

Gallons (US Liquid)

0.00 gal

Total Cubic Feet

0.00 cu ft

Total Liters

0.00 L

Cubic Meters / Barrels

0.00 m³

How This Is Calculated

A cylindrical tank's volume is pi times radius squared times height. A rectangular tank is just length times width times height. Either way, that raw volume converts into gallons, liters, and cubic feet.d scales.

Worked Example

A cylindrical tank 48 inches in diameter and 96 inches tall holds about 752.02 gallons. A rectangular tank with the same 48x48x96 inch footprint holds roughly 957.51 gallons, since it doesn't lose volume to rounded sides.

Common Mistakes

Using diameter instead of radius (or vice versa) when entering cylindrical tank dimensions.
Forgetting a tank's usable capacity is often less than its full geometric volume, due to fill limits, dead space, or fittings.
Assuming this handles dished or elliptical tank ends; it calculates flat-ended cylinders and rectangular boxes only.

Frequently Asked Questions

Does this calculate usable capacity or total volume?: Total geometric volume. Subtract a safety margin for headspace, fittings, or fill limits to get practical working capacity.
Can I use this for a horizontal cylindrical tank?: The volume math is the same regardless of orientation. Just make sure you're entering the correct height/diameter relative to how the tank actually sits.
What if my tank has rounded (dished) ends instead of flat ends?: This calculator assumes flat ends. Dished or elliptical heads add a bit more volume that isn't captured here.

Disclaimer: This tool is provided for educational and informational tracking purposes only. Calculations assume mathematically perfect geometrical boundaries. True containment capacities vary widely due to plate curvature properties, internal structural bracing, fluid thermal expansion variables, and sensor configurations. Wall configurations must be cross-checked manually against engineering drawings by certified mechanical estimators before specifying processing configurations. The website owner assumes no liability.