**Definitions:**

**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.

**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.

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

*Example: How many double square inches are equivalent to 86 double square millimeters?*

As;

1 double square millimeters = 2.4024903900096E-6 double square inches

86 double square millimeters = Y double square inches

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

Y equals 86 times 2.4024903900096E-6 over 1

(i.e.) Y = 86 * 2.4024903900096E-6 / 1 = 0.00020661417354083 double square inches

Answer is: 0.00020661417354083 double square inches are equivalent to 86 double square millimeters.

*Practice Question: Convert the following units into in4:*

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

( i ) 26.28 mm4

( ii ) 83.71 mm4

( iii ) 80.21 mm4