# Pipe volume calculator

Find out how much water a pipe holds based on material, size, and length. Supports copper, PVC, PEX, and steel.

Fill with sample data  
**Pipe material (optional)**  
- Copper (Type L)  
- PVC (Sch 40)  
- CPVC (Sch 40)  
- PEX  
- Black Iron (Sch 40)

**Nominal size**  
- 3/8"  
- 1/2"  
- 3/4"  
- 1"  
- 1-1/4"  
- 1-1/2"  
- 2"  
- 3"  
- 4"  
- Custom

**Pipe length**  
ft

Your volume will appear here, please add:  
**Pipe size**  
**Pipe length**

or  
**Fill with sample data**

You handle the pipes. Workiz handles the rest — scheduling, dispatching, invoicing, and payments, all in one place.

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## How to calculate pipe volume

Pipe volume tells you how much water (or other fluid) sits inside a pipe. You need this number for flushing systems, filling new lines, estimating water heater recovery time, or calculating antifreeze quantities. Guessing leads to waste or shortages — a quick calculation gets you the right amount.

The formula is straightforward (V = π × r² × L), but inside diameter varies by material and nominal size:

1. **Pick the material** — Copper, PVC, PEX, or black steel. Each has different wall thickness and inner diameter.  
2. **Select the size** — The nominal pipe size you are working with.  
3. **Enter the length** — Total run in feet.

Working with temperature changes on long runs? Check the [pipe expansion calculator](/content/tools/pipe-thermal-expansion/index.html) to see how much the pipe will move. Need to price the job? Use the [service price calculator](/content/tools/service-profit/index.html) to build your quote.

## Frequently asked questions

**Why does pipe volume matter for my project?**  
You need an accurate volume calculation whenever fluid quantity is critical — such as filling a new boiler system, flushing a water heater, or estimating how long it takes to get hot water to a fixture.

**Does pipe material change the total volume?**  
Yes. Different materials have different wall thicknesses. For example, a 3/4 inch copper pipe has a larger inside diameter than 3/4 inch PEX, so it holds more liquid. This calculator accounts for these specific material standards.

**How do I convert gallons to liters in this tool?**  
You do not have to. This calculator shows results in both US gallons and liters simultaneously, so it works for any region or project standard.

**What are common pipe sizes for residential plumbing?**  
Main water lines are typically 3/4 inch or 1 inch. Branch lines are usually 1/2 inch for individual fixtures. Drain lines range from 1.5 to 4 inches. Once you identify your size, use this tool to calculate the volume for the entire run.

**How do I measure pipe length for an accurate calculation?**  
Measure the total run from start to end, including vertical sections. Do not forget to account for fittings — each 90-degree elbow adds equivalent length. Entering the full distance ensures you will not come up short on materials or chemicals.