Construction & Materials
Pipe Diameter Calculator
Determine the required pipe diameter to carry a target flow rate at a maximum velocity.
Your inputs
Change any value to update the result instantly.
Required pipe diameter
6.3914 in
Flow rate
1.11 ft³/s
Cross-sectional area
0.223 ft²
Nearest nominal size
7 in
Formula and working
D = √(4Q ÷ (π × Vmax))
- 1
Collect the inputs
Design flow rate = 500 gpm; Maximum velocity = 5 ft/s
- 2
Apply the formula
D = √(4Q ÷ (π × Vmax))
- 3
Result
Required pipe diameter = 6.3914 in
Frequently asked questions
Important limitation
This is an educational estimate based only on the values and formula shown. Verify current rates, rules, units, and professional standards before relying on the result. It is not personalized financial or investment advice.
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