Fluid dynamics calculator

Hydraulic Radius Calculator

Calculate R = A / P for channels and conduits.

Calculator

Enter values

Choose units beside each input. Results update automatically.

Fluid flow

Result

About this calculator

How it works

Hydraulic radius represents the efficiency of a channel cross-section for flow.

Formulas

Formulas used

Hydraulic radius

R = A / P

Guide

How to use this calculator

  1. Enter the known flow, geometry, or fluid property values.
  2. Select the units beside each input where a unit menu is shown.
  3. Read the highlighted result first, then use the table for supporting values.

Reference

What the results mean

Hydraulic radius

Flow area divided by wetted perimeter.

FAQ

Hydraulic Radius Calculator questions

Can I use different units?

Yes. Select the unit beside each input. The calculator converts values internally before solving.

Are these results suitable for final design?

Use results for education, screening, and early design checks. Verify final work against standards, codes, and project requirements.

Why do fluid results depend so much on assumptions?

Fluid calculations depend on geometry, roughness, density, viscosity, coefficients, and flow regime. Use representative input values and confirm assumptions.

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