Tank Size Calculator

Tank Size Calculator

Tank Size Calculator – Calculate Tank Volume Easily

Are you unsure about how much your tank can hold? Whether you’re dealing with water tanks, fuel tanks, chemical storage, or septic systems, our Tank Size Calculator makes it quick and easy to determine total capacity and filled volume — in both cubic meters (m³) and U.S. gallons.

This tool supports multiple tank shapes and unit conversions, making it perfect for contractors, engineers, homeowners, and anyone needing accurate tank volume measurements.

Why Use This Tank Volume Calculator?

  • Supports horizontal, vertical, and rectangular tank shapes

  • Converts inputs from meters, feet, inches, or centimeters

  • Calculates total tank capacity and filled volume

  • Returns results in cubic meters (m³) and gallons

  • No login or registration required — 100% free to use

How to Use the Tank Size Calculator

  1. Select Your Measurement Unit
    Choose the unit you’re most comfortable with:

    • Meters (m)

    • Feet (ft)

    • Inches (in)

    • Centimeters (cm)
      All values are internally converted to meters for accurate volume calculation.

  2. Choose the Tank Shape

    • Horizontal Cylinder: Lying on its side (commonly used for oil, fuel, or LPG tanks)

    • Vertical Cylinder: Standing upright (like water towers or silos)

    • Rectangle (Box Tank): Used in underground storage or septic systems

  3. Enter the Tank Dimensions

    • Length – The horizontal size of the tank

    • Diameter / Height – Vertical height of the cylinder (or height for rectangle)

    • Width – Only for rectangular tanks

    • Filled Depth – (Optional) Enter how full the tank currently is

  4. Click the “Calculate” Button

    • The calculator instantly provides:

      • ✅ Total Tank Volume

      • ✅ Current Filled Volume (if filled depth is provided)

      • Results in both m³ (cubic meters) and gallons

Example Calculation

Example: You have a horizontal cylindrical tank that is:

  • 10 feet long

  • 5 feet in diameter

  • Filled to 3 feet

✅ Select Feet as the unit
✅ Choose Horizontal Cylinder
✅ Enter 10 (Length), 5 (Diameter), 3 (Filled Depth)
✅ Click Calculate

Result:

    • Total Volume: 1.77 m³ (≈ 467.6 gallons)

    • Filled Volume: 1.06 m³ (≈ 279.7 gallons)

Understanding Tank Shapes

Tank ShapeDescriptionCommon Uses
Horizontal CylinderA lying-down tubeOil, fuel, or propane tanks
Vertical CylinderA standing tubeWater storage, silos
RectangleBox-shaped containerSeptic tanks, concrete pits

Supported Units and Conversions

You can input measurements in any of the following units. They are automatically converted into meters (m) for calculation.

UnitConversion to Meters
1 Foot (ft)0.3048 meters
1 Inch (in)0.0254 meters
1 Centimeter (cm)0.01 meters
1 Meter (m)1 meter

Conversion Note:
1 cubic meter (m³) = 264.172 U.S. gallons

Frequently Asked Questions (FAQ)

Can I calculate how much my tank is filled?

Yes! Just enter the filled depth to get the filled volume alongside the total volume. However, you can use our septic tank size calculator to easily determine the right size septic tank for your needs.

What units can I enter?

You can use meters, feet, inches, or centimeters. The calculator will handle all the conversions.

Are the results in U.S. or Imperial gallons?

We use U.S. liquid gallons.
1 m³ = 264.172 U.S. gallons

Is this calculator suitable for underground tanks?

Absolutely. As long as you know the tank dimensions, you can calculate volume accurately.

Can I use this for fuel or chemical tanks?

Yes! This calculator is ideal for estimating the volume of tanks used in fuel, oil, chemicals, and other industrial storage.

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