MM → Inches
12.7 mm to inches
12.7 millimeters equals 0.5 inches — or about 1/2" (nearest 1/16″).
Decimal
0.5 in
Fraction
1/2"
Centimeters
1.27 cm
Feet
0.0417 ft
mm
0.5
in≈ 1/2" (nearest 1/16)
1 in = 25.4 mm · tolerance ±0.0001
Formula
To convert mm to inches, divide by 25.4:
inches = mm ÷ 25.4
inches = 12.7 ÷ 25.4 = 0.5
Why 12.7 mm = 0.5 in
Since 1 inch is defined as exactly 25.4 millimeters, 12.7 mm converts to 0.5 inches. Rounded to the nearest 1/16″ that's 1/2", which is what you'd read off a standard imperial ruler.