40 inches in cm

101.6 cm

40 in = 101.6 cm = 1016 mm = 1.016 m

Working: 40 × 2.54 = 101.6

40 inches is 101.6 centimetres, or 1016 millimetres.

The conversion is exact rather than approximate: since 1959 the international inch has been defined as precisely 2.54 centimetres, so multiplying by 2.54 gives an exact answer with no rounding error. 40 × 2.54 = 101.6 cm. To go back the other way, divide by 2.54; for millimetres, multiply the inches by 25.4 instead.

Metric trades work in millimetres rather than centimetres, and 40 inches is 1016 mm — the figure a drawing or a parts list would actually carry. The nearest whole centimetre is 102, 0.4 cm away. In feet that is 3.33.

Forty inches is a common mid-range television size, at 101.6 cm diagonally. This is where the gap between the advertised diagonal and the usable width becomes significant: the panel is about 89 cm wide, nearly 13 cm less than the headline figure suggests.

Nearby lengths

Inches	Centimetres
15 in	38.1 cm
18 in	45.72 cm
24 in	60.96 cm
27 in	68.58 cm
32 in	81.28 cm
48 in	121.92 cm
55 in	139.7 cm
65 in	165.1 cm

Try another value

From

3.2808ft

All units

Millimeters1,000 mm

Centimeters100 cm

Meters1 m

Kilometers0.001 km

Inches39.3701 in

Feet3.2808 ft

Yards1.0936 yd

Miles0.00062137 mi

Nautical miles0.00053996 nmi

Frequently asked questions

How many cm is 40 inches?

40 inches is 101.6 cm. Multiply the number of inches by 2.54 to convert to centimetres.

Is the inch to cm conversion exact?

Yes. The international inch has been defined as exactly 2.54 centimetres since 1959, so the conversion introduces no rounding error.

For any other value, use the full Length Converter on BrainVert.