MM → Inches
2.1 mm to inches
2.1 millimeters equals 0.082677 inches — or about 1/16" (nearest 1/16″).
Decimal
0.0827 in
Fraction
1/16"
Centimeters
0.21 cm
Feet
0.0069 ft
mm
0.082677
in≈ 1/16" (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 = 2.1 ÷ 25.4 = 0.082677
Why 2.1 mm = 0.0827 in
Since 1 inch is defined as exactly 25.4 millimeters, 2.1 mm converts to 0.082677 inches. Rounded to the nearest 1/16″ that's 1/16", which is what you'd read off a standard imperial ruler.