To answer this question, we have to know that 1 mm is approximately equal to 0.0393701 inches. Therefore to convert a length in mm to a length in inches, we simply need to take the length in mm and multiply it by 0.0393701 which will provide us with the length in inches. In this case we would have and mathematically express

20 mm = 20 * 0.0393701 inches = 0.787402 inches.

Notice that the answer is not exact because there is no analytical exact conversion between mm and inches. Therefore, 20 mm in inches is approximately 0.787402 inches.

I hope this answers your question and allows you to convert between a length in mm and inches in the future. Good Luck!

1 inch = 2.54 cm

1 cm = 10 mm

1 inch = 2.54 cm = 25.4 mm

Since 25.4 mm = 1 inch,

therefore 20 mm = 20/25.4 inch

Â = 0.78 inches

Thus, there are 0.78 inches in 20 mm.

the formula for this calculation is

in =mm * 0.039370

So 20mm = 20 * .039370 which calculates to

20mm = 0.7874 inches

20 millimetres = 0.787401575 inches but you'd probably want to round that off, so around 0.79

inches