**Definitions:**

**Millimeter** (abbreviation: **mm**): is a unit of length in the SI metric system, equal to one thousandth of a metre. Therefore, there are thousand millimetres in a metre and ten millimetres in a centimetre.

**Inch** (abbreviation: **in**): is a unit of length in the (British) imperial and United States customary systems of measurement now formally equal to 1/36 yard but usually taken as 1/12 of a foot.

## How to Convert Millimeters to Inches

*Example: How many inches are equivalent to 80.09 millimeters?*

As;

1 millimeters = 0.03937 inches

80.09 millimeters = Y inches

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

Y equals 80.09 times 0.03937 over 1

(i.e.) Y = 80.09 * 0.03937 / 1 = 3.1531433 inches

Answer is: 3.1531433 inches are equivalent to 80.09 millimeters.

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

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

( i ) 14.67 mm

( ii ) 98.92 mm

( iii ) 71.51 mm