Online Fluid Velocity Calculator.

## Fluid Velocity Formulas:

**Imperial Units:**

V = ( 0.409 * Q ) / d^{2}.

where:

V = velocity, ft/s.

Q = flow, gpm.

d = pipe inside diameter, in.

**SI Units:**

V = ( 354 * Q ) / d^{2}.

where:

V = velocity, m/s.

Q = flow, m3/h.

d = pipe inside diameter, mm.