Radius of Gyration in Structural Engineering

This calculation tool is designed to help you quickly and accurately determine the radius of gyration for a cross-section. Enter custom section values or select a cross-section for the AISC section size database.
CalculationInputs﻿﻿Moment of Inertia, I
:100.00mm4​
﻿
﻿﻿Area, A
:4.00mm2​
﻿
Output﻿﻿r
:5.00mm​
﻿
﻿
r=IAr = \sqrt{\frac{I}{A}}r=AI​​
Select from standard AISC sizes﻿﻿Designation
:W44X408​
﻿
﻿
﻿﻿rx,
:18in​
﻿
﻿﻿ry
:3.56in​
﻿
ExplanationA radius of gyration is defined as the distance from the centre of mass of a body at which the whole mass is concentrated (without changing the moment of rotational inertia) about an axis through the centre of mass. 
The radius of gyration is defined as the distance from the Neutral axis to the strip where the area is assumed and is calculated using the formula:
﻿
r=IAr = \sqrt{\frac{I}{A}}r=AI​​
Here are the variables for the equation
﻿﻿r
 = Radius of Gyration
﻿﻿I
 = Moment of Inertia
﻿﻿A
 = Area
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