**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.

**Mile** (abbreviation: **mi**): is an English unit of length of distance equal to 5,280 feet, or 1,760 yards, and standardised as exactly 1,609.344 metres by international agreement in 1959.

## How to Convert Millimeters to Miles

*Example: How many miles are equivalent to 68.71 millimeters?*

As;

1 millimeters = 6.21E-7 miles

68.71 millimeters = Y miles

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

Y equals 68.71 times 6.21E-7 over 1

(i.e.) Y = 68.71 * 6.21E-7 / 1 = 4.266891E-5 miles

Answer is: 4.266891E-5 miles are equivalent to 68.71 millimeters.

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

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

( i ) 21.24 mm

( ii ) 5.49 mm

( iii ) 23.54 mm