MM → Inches
45 mm to inches
45 millimeters equals 1.771654 inches — or about 1 3/4" (nearest 1/16″).
Decimal
1.7717 in
Fraction
1 3/4"
Centimeters
4.5 cm
Feet
0.1476 ft
mm
1.771654
in≈ 1 3/4" (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 = 45 ÷ 25.4 = 1.771654
Why 45 mm = 1.7717 in
Since 1 inch is defined as exactly 25.4 millimeters, 45 mm converts to 1.771654 inches. Rounded to the nearest 1/16″ that's 1 3/4", which is what you'd read off a standard imperial ruler.