Convert Inch to Millimeter (in to mm)

In next fields, kindly type your value in the text box under title [ From: ] to convert from inch to millimeter (in to mm). As you type your value, the answer will be automatically calculated and displayed in the text box under title [ To: ].


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.

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.

How to Convert Inches to Millimeters

Example: How many millimeters are equivalent to 34.21 inches?


1 inches = 25.4 millimeters

34.21 inches = Y millimeters

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

Y equals 34.21 times 25.4 over 1

(i.e.) Y = 34.21 * 25.4 / 1 = 868.934 millimeters

Answer is: 868.934 millimeters are equivalent to 34.21 inches.

Practice Question: Convert the following units into mm:

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

( i ) 59.56 in

( ii ) 5.64 in

( iii ) 73.45 in

Convert Inch to More Length Units

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