Froude Number Calculator

Calculate the Froude Number (Fr) to determine the flow regime of an open channel (subcritical, critical, or supercritical). This dimensionless number is heavily used in fluid mechanics, hydrology, and naval architecture.

Froude Number Calculator

For open channels, use the hydraulic depth. For boats, use hull length.

How to Use

  1. 1

    Enter Flow Velocity

    Input the mean velocity of the fluid or the speed of the vessel in meters per second (m/s).

  2. 2

    Enter Characteristic Length

    For open channels, enter the hydraulic depth. For boats/ships, enter the waterline length.

  3. 3

    Calculate

    Click calculate to view the Froude number and immediately see whether the flow is subcritical or supercritical.

Frequently Asked Questions

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