Pipe Flow Calculator

Flow rate Q = A × v, where A is the pipe cross-sectional area (π × r²) and v is the flow velocity. For a 2-inch pipe at 5 ft/s: A = π × (1/12)² = 0.0218 ft², Q = 0.0218 × 5 = 0.109 ft³/s = 48.9 GPM.

For residential plumbing, typical water velocity is 4-8 ft/s. Velocities above 8 ft/s can cause noise and pipe erosion. For fire sprinkler systems, maximum velocity is typically 20 ft/s.