MM → Inches

40 mm to inches

40 millimeters equals 1.574803 inches — or about 1 9/16" (nearest 1/16″).

Decimal

1.5748 in

Fraction

1 9/16"

Centimeters

4 cm

Feet

0.1312 ft

Millimeters (mm)

Inches (in)

1.574803

≈ 1 9/16" (nearest 1/16)

1 in = 25.4 mm · tolerance ±0.0001

Nearby values

39 mm 41 mm 38.5 mm 38.1 mm 38 mm 42 mm 37.5 mm 37 mm 43 mm 36 mm

Precision

1.5748

Inches

40.0 mm · max 100

Ref · 25.4 mm/in

Drag to set

Formula

To convert mm to inches, divide by 25.4:

inches = mm ÷ 25.4
inches = 40 ÷ 25.4 = 1.574803

Why 40 mm = 1.5748 in

Since 1 inch is defined as exactly 25.4 millimeters, 40 mm converts to 1.574803 inches. Rounded to the nearest 1/16″ that's 1 9/16", which is what you'd read off a standard imperial ruler.