MM → Inches
210 mm to inches
210 millimeters equals 8.267717 inches — or about 8 1/4" (nearest 1/16″).
Decimal
8.2677 in
Fraction
8 1/4"
Centimeters
21 cm
Feet
0.689 ft
mm
8.267717
in≈ 8 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 = 210 ÷ 25.4 = 8.267717
Why 210 mm = 8.2677 in
Since 1 inch is defined as exactly 25.4 millimeters, 210 mm converts to 8.267717 inches. Rounded to the nearest 1/16″ that's 8 1/4", which is what you'd read off a standard imperial ruler.