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Pipe Flow Rate Calculator
Find flow rate from pipe diameter and water velocity.
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Find flow rate from pipe diameter and water velocity.
Pipe Flow Rate Estimator
Enter your numbers below for an instant estimate.
0
π‘ Tip: Domestic water pipes are usually sized for 1 to 2 m/s.
How It Works
Key concepts behind this calculator
1
Enter Values
Fill in each field with your own numbers.
2
Calculate
Results update as you change the inputs.
3
Review
Read the breakdown and the explanation.
4
Adjust
Change values to compare scenarios.
Quick Reference Guide
Pipe Quick Guide
Typical values for reference.
| Pipe mm | Flow at 1.5 m/s L/s | L/min | Note |
|---|---|---|---|
| 15 | 0.27 | 16 | Tap |
| 25 | 0.74 | 44 | Shower |
| 50 | 2.95 | 177 | Main |
| 100 | 11.8 | 707 | Large |
| Rule of Thumb | Check inputs | Use as a guide | Round sensibly |
Common Questions
Pipe Flow Rate Calculator FAQ
Answers to common questions about this calculator.
Area times velocity.
1 to 2 m/s for most building water.
Yes for pressure loss, not for this rate.
This tool shows several units.