Calculator ng Dami ng Tangke

Understanding Tank Volume Calculations

Calculating storage tank volume is a fundamental requirement across industrial processing, fuel distribution, agriculture, and municipal water management. Depending on whether a tank is oriented vertically or horizontally, the mathematical approach changes dramatically.

1. Vertical Cylindrical Tanks

Vertical tanks are the simplest to calculate because the cross-sectional area remains constant from bottom to top:

• Total Volume = π × r² × H
• Liquid Volume = π × r² × d

Where r is the inside radius, H is the total height, and d is the measured liquid depth. Because the cross-section is uniform, fluid volume increases directly in proportion to fluid depth.

2. Horizontal Cylindrical Tanks

Horizontal tanks are widely used for underground fuel storage (USTs), propane, and bulk chemicals. Because the cylinder lies on its side, the fluid surface width expands until it reaches the centerline (d = r) and then narrows toward the top.

To determine the volume at liquid depth d:

1. Calculate the circle’s central angle θ: θ = 2 × arccos((r - d) / r)
2. Find the area of the filled circular segment A: A = 0.5 × r² × (θ - sin θ)
3. Multiply by the horizontal cylinder length L: Liquid Volume = A × L

Horizontal fuel tank – calculation example

Let’s find the current fuel volume of a horizontal storage tank with diameter 48 inches (radius 24 in), length 120 inches, and dipstick liquid level of 12 inches:

1. Tank radius: radius = 24 inches.
2. Tank length: length = 120 inches.
3. Dipstick liquid depth: depth = 12 inches.
4. The calculation results are available for you: total capacity = 940 US gallons, current liquid volume = 184 US gallons, and percent full = 19.6%.

💡 In a horizontal cylinder, 1 inch of dipstick reading near the midpoint holds up to 3 times more volume than 1 inch near the bottom or top.

3. Rectangular & Flat-Walled Tanks

For rectangular prism containers (such as basement heating oil tanks or concrete cisterns):

• Total Volume = Length × Width × Height
• Liquid Volume = Length × Width × Depth