Water Supply Line Size Calculator
Pick a pipe size for a water supply line from flow rate and a velocity limit.
Compare Your Options And Get Clear Answers
Pick a pipe size for a water supply line from flow rate and a velocity limit.
Water Supply Line Size Estimator
Enter your numbers below for an instant estimate.
How It Works
Key concepts behind this calculator
Enter Values
Fill in each field with your own numbers.
Calculate
Results update as you change the inputs.
Review
Read the breakdown and the explanation.
Adjust
Change values to compare scenarios.
Water Quick Guide
Typical values for reference.
| L/min | Velocity | Length m | Diameter mm |
|---|---|---|---|
| 10 | 1.5 | 20 | 11.9 mm |
| 25 | 1.5 | 20 | 18.8 mm |
| 40 | 1.5 | 20 | 23.8 mm |
| 100 | 1.5 | 40 | 37.6 mm |
| Rule of Thumb | Check inputs | Use as a guide | Round sensibly |
Water Supply Line Calculator FAQ
Answers to common questions about this calculator.
Choose a diameter that keeps velocity under about 2 m/s at peak flow.
Often yes, to limit friction loss over distance.
Diameter = square root of (4 x flow / (pi x velocity)).
It is an estimate based on the inputs you enter. Check real quotes, labels or official guidance for important decisions.