Pipe Sizing Calculator
Calculate optimal pipe diameters for water supply systems based on flow rate, velocity limits, and pressure drop. Supports copper, PVC, PPR, galvanized steel, and HDPE pipes with Hazen-Williams friction calculations.
Volume flow rate in liters per second
Recommended velocity: 0.6 - 2.5 m/s
Hazen-Williams coefficient affects friction loss
Optional: Override the default max velocity for your fluid type
Enter flow parameters and click Calculate to see pipe sizing results
Notes:
- Calculations based on Hazen-Williams formula for friction loss
- Reynolds number determines flow regime (laminar/turbulent)
- Velocity should be within recommended range to prevent noise and erosion
- Consider pressure requirements and system constraints
- For fire systems, consult local codes for minimum requirements
DISCLAIMER
This calculator provides ESTIMATES for preliminary planning purposes. Results are based on standard assumptions and may not reflect your specific project conditions.
By using this tool, you acknowledge that:
1. All calculations are approximate and based on typical industry standards and assumptions.
About This Calculator
The Pipe Sizing Calculator helps MEP engineers and plumbing contractors determine optimal pipe diameters for water supply systems across the UAE and Gulf. Calculate required pipe sizes based on flow rate, velocity limits, and pressure drop using the Hazen-Williams friction formula. Supports common pipe materials including copper, PVC, PPR, galvanized steel, and HDPE used in Gulf construction projects.
When to Use This Calculator
- Designing domestic water supply systems for buildings
- Sizing main distribution pipes and branch lines
- Checking velocity compliance (typically 1.5-3 m/s for hot/cold water)
- Calculating pressure drop for pump selection
- Verifying pipe specifications for tender submissions
How to Use This Calculator
Enter Flow Rate
Input the required flow rate in liters per second (L/s) or gallons per minute (GPM).
Select Pipe Material
Choose from copper, PVC, PPR, galvanized steel, or HDPE - each has different friction coefficients.
Set Velocity Limits
Specify maximum velocity (typically 1.5-2 m/s for quiet systems, up to 3 m/s for mains).
Enter Pipe Length
Input the total equivalent length including fittings for pressure drop calculation.
Review Results
Get recommended pipe diameter, actual velocity, and pressure drop per 100m.
Typical Scenarios in UAE & Gulf Projects
A plumbing contractor sizes the main cold water line for a 5-bedroom villa with a peak design flow of 2.5 L/s in PPR. With the default 2.5 m/s limit for cold water, the calculator selects DN40 at 1.99 m/s (DN32 would run at 3.11 m/s), with a Hazen-Williams friction loss of about 9.7 m per 100 m (about 95 kPa/100 m). On a long run, stepping up to DN50 (1.27 m/s) cuts the friction loss substantially.
An MEP consultant sizes the main cold water riser for a hotel at 15 L/s in copper. The calculator selects DN100 at 1.91 m/s (DN80 would run at 2.98 m/s), with a friction loss of about 3.5 m per 100 m (about 34 kPa/100 m). Pump head and pressure zoning still need a full hydraulic calculation and the water utility's connection requirements.
Frequently Asked Questions
Take Your Calculations Further
This calculator reflects the logic built into Arkan's construction management platform.
Last Updated: January 2026
Standards Reference: Hazen-Williams formula, ASHRAE Handbook, DEWA/ADDC Plumbing Codes