🛢️Cylindrical Cistern Capacity Calculator Round Tank Capacity

Calculate round tank capacity in gallons, liters, cubic feet, and cubic meters

📏 Tank Dimensions

💡 How to Use This Cylindrical Tank Volume Calculator

This calculator helps you determine the exact capacity of any cylindrical tank, whether it's a water storage tank, fuel tank, silo, or pressure vessel. Simply follow these steps:

  • Step 1: Enter the diameter (or radius) and height of your tank.
  • Step 2: Select your measurement unit (Feet, Meters, Centimeters, or Inches).
  • Step 3: Choose whether to input diameter or radius.
  • Step 4: Optionally set the fill level percentage to calculate partial volume.
  • Step 5: Click "Calculate Tank Volume" to see results in multiple units.

The calculator instantly converts between cubic feet, cubic meters, US gallons, and liters — no manual conversions needed!

📐 Cylindrical Tank Volume Formula

The volume of a cylindrical tank is calculated using the formula:

V = π × r² × h

Where:

  • V = Volume of the tank
  • π = Pi (approximately 3.14159)
  • r = Radius of the tank (half the diameter)
  • h = Height of the tank

If you have the diameter instead of radius, remember: r = D ÷ 2

Once you have the volume in cubic units, use these conversion factors:

FromToMultiply By
Cubic Feet (ft³)US Gallons7.48052
Cubic Feet (ft³)Liters28.3168
Cubic Meters (m³)US Gallons264.172
Cubic Meters (m³)Liters1000
Cubic Inches (in³)US Gallons0.004329
Cubic Centimeters (cm³)Liters0.001

🏭 Common Applications

💧 Water Storage Tanks

Calculate the capacity of residential or commercial cylindrical water tanks. Cylindrical tanks are preferred for water storage because they distribute pressure evenly and are structurally efficient.

⛽ Fuel & Oil Tanks

Determine storage capacity for diesel, gasoline, or oil tanks. Many fuel stations use cylindrical underground storage tanks (USTs) that require accurate volume calculations for inventory management.

🌾 Agricultural Silos

Calculate grain storage capacity in cylindrical silos. Knowing the exact volume helps farmers plan harvest storage and manage inventory.

🏭 Industrial Pressure Vessels

Engineers use cylindrical tank calculations for designing boilers, reactors, and pressure vessels where round shapes provide optimal strength.

🏊 Swimming Pools

Round above-ground pools are common residential options. Calculate water volume for chemical treatment and heating requirements.

📏 Cylindrical Tank Sizing Guide

Here are common cylindrical tank sizes and their approximate capacities:

Diameter (ft)Height (ft)Volume (ft³)GallonsLiters
3428.3212801
4562.84701,778
56117.88813,336
68226.21,6926,406
810502.73,76014,235
1012942.57,05026,693
12151,696.512,69048,048

❓ Frequently Asked Questions

How do you calculate the volume of a cylindrical tank?
The volume of a cylindrical tank is calculated using the formula: Volume = π × r² × h, where r is the radius (half the diameter) and h is the height. For example, a tank with 4 ft diameter (2 ft radius) and 5 ft height has a volume of π × 2² × 5 = 62.83 cubic feet.
How many gallons is my cylindrical tank?
Multiply the cubic feet volume by 7.48052 to get US gallons. For metric: cubic meters × 264.172 = gallons, or liters ÷ 3.78541 = gallons.
What is the formula for tank capacity in liters?
For dimensions in meters: π × r² × h × 1000 = Liters. For dimensions in centimeters: (π × r² × h) ÷ 1000 = Liters. For dimensions in feet: cubic feet × 28.3168 = Liters.
How do I calculate the radius if I only have the diameter?
The radius is exactly half the diameter. If your tank has a diameter of 6 feet, the radius is 3 feet. This calculator lets you input either diameter or radius.
What's the difference between US gallons and Imperial gallons?
This calculator uses US gallons (1 US gal = 3.78541 liters). Imperial gallons (UK) are larger: 1 Imperial gal = 4.54609 liters. Multiply US gallons by 0.832674 to get Imperial gallons.
How much does the water weigh in a cylindrical tank?
Water weighs approximately 8.34 pounds per US gallon or 1 kilogram per liter. This calculator shows the total water weight at full capacity to help with structural load calculations for tank stands and foundations.
Why are cylindrical tanks so common?
Cylindrical tanks are popular because they have no corners where stress concentrates, making them structurally stronger. They also require less material for the same volume compared to rectangular tanks and are easier to manufacture and transport.