Moments of Inertia of Common Shapes
rectangle
x'
=
1
12
bh
3
y'
=
1
12
b
3
h
I
x
=
1
3
bh
3
I
y
=
1
3
b
3
h
J
C
=
1
12
bh
(
b
2
+
h
2
)
triangle
x'
=
1
36
bh
3
y'
=
1
12
bh
3
circle
x
=
y
=
1
4
πr
4
J
O
=
1
2
πr
4
semicircle
I
x
=
I
y
=
1
8
πr
2
J
O
=
1
4
πr
4
quarter circle
I
x
=
I
y
=
1
16
πr
4
J
O
=
I
z
=
1
8
πr
4
ellipse
x
=
1
4
πab
3
y
=
1
4
πa
3
b
J
O
=
1
4
πab
(
a
2
+
b
2
)