**Definitions:**

**Double Square Inch** (abbreviations: **in4, or in 4**): is a unit in the (British) imperial and United States customary systems of measurement of area moment of inertia, a geometrical property of an area which reflects how its points are distributed with regard to an arbitrary axis.

**Double Square Millimeter** (abbreviations: **mm4, or mm 4**): is the SI derived unit of area moment of inertia, a geometrical property of an area which reflects how its points are distributed with regard to an arbitrary axis.

## How to Convert Double Square Inches to Double Square Millimeters

*Example: How many double square millimeters are equivalent to 86.33 double square inches?*

As;

1 double square inches = 416231.4256 double square millimeters

86.33 double square inches = Y double square millimeters

Assuming Y is the answer, and by criss-cross principle;

Y equals 86.33 times 416231.4256 over 1

(i.e.) Y = 86.33 * 416231.4256 / 1 = 35933258.972048 double square millimeters

Answer is: 35933258.972048 double square millimeters are equivalent to 86.33 double square inches.

*Practice Question: Convert the following units into mm4:*

N.B.: After working out the answer to each of the next questions, click adjacent button to see the correct answer.

( i ) 40.31 in4

( ii ) 74.5 in4

( iii ) 30.84 in4