MM → Inches
6.5 mm to inches
6.5 millimeters equals 0.255906 inches — or about 1/4" (nearest 1/16″).
Decimal
0.2559 in
Fraction
1/4"
Centimeters
0.65 cm
Feet
0.0213 ft
mm
0.255906
in≈ 1/4" (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 = 6.5 ÷ 25.4 = 0.255906
Why 6.5 mm = 0.2559 in
Since 1 inch is defined as exactly 25.4 millimeters, 6.5 mm converts to 0.255906 inches. Rounded to the nearest 1/16″ that's 1/4", which is what you'd read off a standard imperial ruler.