Pipe Volume Calculator
Calculate the liquid holding capacity (volume, gallons, and liters) inside a pipe based on its inner diameter and length.
Calculation Results
Total holding capacity of the pipe in cubic feet.
Total pipe holding capacity in US liquid gallons.
Total pipe holding capacity in liters.
How This Calculator Works
To calculate fluid volume inside a pipeline:
- Enter the inside diameter of the pipe (standard unit is inches; make sure to use inside diameter, not outside diameter).
- Enter the total run length of the pipe.
- The calculator determines total capacity in cubic feet, gallons, and liters.
Formula & Calculations
Pipe volume is calculated using the cylinder volume formula based on the pipe's internal diameter and length:
Volume = π × (Diameter / 2)² × Length
Liquid unit capacities are scaled from the base cubic feet value:
- US Gallons: Multiply cubic feet by
7.4805(or divide by0.133681). - Liters: Multiply cubic feet by
28.3168(or divide by0.03531467).
Step-by-Step Calculation Examples
Common Water Line (2" diameter, 100ft length)
Calculating the fluid storage capacity of a 100-foot run of standard 2-inch diameter irrigation pipe.
- diameter: 2
- length: 100
- volume_cu_ft: 2.18 cu ft
- volume_gallons: 16.3 gal
- volume_liters: 61.8 L
Frequently Asked Questions
Should I use inside or outside diameter for pipe volume?
Always use the Inside Diameter (ID). The Outside Diameter (OD) includes the thickness of the pipe walls. Using OD will lead to an overestimation of actual holding volume.
How many gallons of water are in a foot of 2-inch pipe?
A standard 2-inch inside diameter pipe holds approximately 0.163 gallons of water per linear foot.
How do you calculate pipe volume in metric units?
In metric units, the formula is the same: Volume = π × radius² × length. If you use centimeters for radius and length, dividing the resulting volume by 1,000 gives liters.
What is the volume of a 4-inch pipe per foot?
A standard 4-inch inside diameter pipe holds approximately 0.653 gallons of water per linear foot (four times the capacity of a 2-inch pipe).
How much does water inside a pipe weigh?
Water weighs approximately 8.34 pounds (3.78 kg) per US gallon, or 62.4 pounds per cubic foot. A full 100-foot run of 2-inch pipe holds about 136 pounds of water.