Velocity Head Calculator

Kinetic energy per unit weight of flow — one of the three head terms in Bernoulli's equation.

Fluid Mechanics I

Inputs

Flow velocity V (m/s)

Fluid density (optional — for dynamic pressure) ρ (kg/m³)

If provided, dynamic pressure q = ½ρV² is also shown.

Theory

Velocity head:

hv = V² / (2g)

Bernoulli's equation (head form):

P/(ρg) + V²/(2g) + z = constant

Pressure head + velocity head + elevation head = total head [m]

Relationship to dynamic pressure:

q = ½ρV² = ρg × hv

Velocity head is used extensively in pipe flow for minor loss calculations (ΔhL = K × hv, where K is the loss coefficient), and appears directly in Bernoulli's equation as the kinetic energy head.