MM → Inches
2.5 mm to inches
2.5 millimeters equals 0.098425 inches — or about 1/8" (nearest 1/16″).
Decimal
0.0984 in
Fraction
1/8"
Centimeters
0.25 cm
Feet
0.0082 ft
mm
0.098425
in≈ 1/8" (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 = 2.5 ÷ 25.4 = 0.098425
Why 2.5 mm = 0.0984 in
Since 1 inch is defined as exactly 25.4 millimeters, 2.5 mm converts to 0.098425 inches. Rounded to the nearest 1/16″ that's 1/8", which is what you'd read off a standard imperial ruler.