Tank Volume Calculator
Calculate volume for tanks, pipes, ponds, and pools — cylindrical, rectangular, or spherical.
Need to convert volume units between liters, gallons, and cubic measurements? Try our Unit Conversion Calculator.
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Formulas
Cylinder: V = π × r² × h
Understanding Tank Volume Calculations
Accurately calculating tank volume is essential for industrial storage, water treatment, chemical processing, and agricultural applications. Whether you're sizing a water tank, estimating pool capacity, or determining chemical storage requirements, knowing the exact volume prevents costly overflows and shortages.
Volume Formulas by Shape
For partial fills, vertical tanks (cylinder, rectangle, cone) scale linearly with fill height. Horizontal cylinders require circular segment geometry — the filled cross-sectional area is calculated using the chord height, then multiplied by the tank length.
How to Calculate Tank Volume
Frequently Asked Questions
How do I calculate tank volume?
It depends on the shape. For a cylinder: V = π × r² × h. For a rectangle: V = l × w × h. For a sphere: V = (4/3) × π × r³. Measure the tank's internal dimensions and apply the correct formula. This calculator handles all five common tank shapes automatically.
How do I calculate a partially filled horizontal cylinder?
A horizontal cylinder's partial fill volume requires the circular segment area. If the fill height is h and the radius is r, the filled area = r² × arccos((r−h)/r) − (r−h) × √(2rh − h²). Multiply this area by the cylinder length to get the volume.
How many gallons are in a 1000L tank?
1 liter = 0.264172 US gallons. So a 1000L tank holds approximately 264.17 US gallons. For Imperial gallons, 1 liter = 0.219969 Imperial gallons, giving about 219.97 Imperial gallons.
How do I calculate pipe volume?
A pipe is a cylinder. Use V = π × (inner diameter / 2)² × length. For example, a 2-inch inner diameter pipe that is 10 feet long: radius = 1 in = 0.0833 ft, V = π × 0.0833² × 10 = 0.218 ft³ ≈ 1.63 US gallons.
What size septic tank do I need?
Septic tank sizing is based on bedrooms and daily wastewater flow. A typical 3-bedroom home needs a 1,000–1,500 gallon tank. A 4-bedroom home typically requires 1,250–1,500 gallons. Local codes may require larger tanks or specific sizing formulas based on daily flow rates.