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Calcimator

Pipe Flow Rate Calculator

Calculate water flow rate, velocity, and friction loss based on pipe diameter, pressure, length, and material.

Inputs

in
PSI
ft

Results

Flow Rate

1.05 GPM

Velocity0.76 ft/s
Friction Loss40 PSI/100ft
Total Head Loss92.4 ft
Flow Rate (metric)3.98 L/min

Flow Rate

1.05 GPM

How to Use This Calculator
  1. Start by filling in the input fields below. Results update instantly as you type, so you can experiment with different values to see how they affect the outcome.
  2. Pipe Diameter — Interior diameter of the pipe in inches. Accepts values from 0.25 in to 12 in (default: 0.75 in).
  3. Pressure — Available water pressure at the supply point. Accepts values from 1 PSI to 150 PSI (default: 40 PSI).
  4. Pipe Length — Total length of the pipe run in feet. Accepts values from 1 ft to 5,000 ft (default: 100 ft).
  5. Pipe Material — Pipe material affects friction coefficient and flow capacity. Choose from: Copper, PVC / CPVC, Galvanized Steel, PEX. default: 1.
  6. Once all inputs are set, review your results in the Results panel. Here's what each output means:
  7. Flow Rate — shown as a numeric value. This is the primary result of this calculator.
  8. Velocity — shown as a numeric value.
  9. Friction Loss — shown as a numeric value.
  10. Total Head Loss — shown as a numeric value.
  11. Flow Rate (metric) — shown as a numeric value.
  12. Explore the related calculators below if you need deeper analysis or want to approach this topic from a different angle.
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