🌊 Froude Number Calculator
Calculate the Froude number — a dimensionless value comparing flow velocity to wave propagation speed — used in hydraulics and naval architecture.
1
m/s
2
m
What Is the Froude Number?
The Froude number is a dimensionless ratio comparing inertial forces to gravitational forces in a flow. It’s widely used in open-channel hydraulics and ship hull design to characterize wave-making behavior.
The Formula
Fr = v / √(gL), where v is flow velocity, g is gravitational acceleration, and L is a characteristic length (such as water depth or hull waterline length). Fr < 1 indicates subcritical (tranquil) flow, Fr = 1 is critical flow, and Fr > 1 is supercritical (rapid) flow.
For general educational purposes.
Last reviewed August 2026