1 inch = 2.54 cm
1 in = 2.54 cm · type math like (12*4)+6.5
Inches to centimeters is the conversion Americans and Britons need when they shop, build or fill in forms for a metric country. It is essential for TV and monitor sizes, sewing patterns, bike frames, and any US product listing that must be shown to customers who only know metric sizes.
Body measurements are another big use. Bra band sizes, inseams and shirt collars are quoted in inches in the US and UK but in centimeters in continental Europe. A 32 inch inseam is 81.3 cm and a 15.5 inch collar is 39.4 cm, which European shirt makers usually label as 39 or 40.
cm = in × 2.54
Reverse: 1 cm = 0.39370079 in.
A sewing pattern calls for a hem allowance of 1 3/4 inches. How many centimeters is that?
Answer: 1 3/4 inches = 4.445 cm, about 4.4 cm.
| in | cm |
|---|---|
| ¼ in | 0.635 cm |
| ½ in | 1.27 cm |
| ¾ in | 1.905 cm |
| 1 in | 2.54 cm |
| 2 in | 5.08 cm |
| 3 in | 7.62 cm |
| 4 in | 10.16 cm |
| 5 in | 12.7 cm |
| 6 in | 15.24 cm |
| 7 in | 17.78 cm |
| 8 in | 20.32 cm |
| 9 in | 22.86 cm |
| 10 in | 25.4 cm |
| 11 in | 27.94 cm |
| 12 in | 30.48 cm |
| 13 in | 33.02 cm |
| in | cm |
|---|---|
| 14 in | 35.56 cm |
| 15 in | 38.1 cm |
| 16 in | 40.64 cm |
| 17 in | 43.18 cm |
| 18 in | 45.72 cm |
| 19 in | 48.26 cm |
| 20 in | 50.8 cm |
| 25 in | 63.5 cm |
| 30 in | 76.2 cm |
| 40 in | 101.6 cm |
| 50 in | 127 cm |
| 75 in | 190.5 cm |
| 100 in | 254 cm |
| 250 in | 635 cm |
| 500 in | 1 270 cm |
| 1 000 in | 2 540 cm |
A 55 inch TV has a diagonal of 55 × 2.54 = 139.7 cm. In many European shops the same set is labelled 139 cm.
US Letter paper is 8.5 × 11 inches, which is 21.59 × 27.94 cm. A4 is 21.0 × 29.7 cm, so Letter is wider but shorter.
North American walls put studs 16 inches apart on center, which is 40.64 cm. European drywall boards are designed around 60 cm spacing instead.
2.5 is easy but wrong. On a 60 inch measurement it gives 150 cm instead of 152.4 cm, a 2.4 cm gap that ruins a fitted shelf.
For 5 ft 9 in, convert everything into inches before multiplying: (5 × 12) + 9 = 69 inches, then 69 × 2.54 = 175.26 cm.
5 3/8 inches is 5.375 inches, not 5.38 or 5.3. Turn the fraction into a decimal exactly, then multiply by 2.54.
The international inch is exactly 25.4 millimeters, or 2.54 centimeters. It is one twelfth of a foot and one thirty-sixth of a yard.
Origin. Anglo-Saxon England measured the inch as three barleycorns, and King Edward II's statute of 1324 repeated that rule. The US and UK inches differed by a few parts per million until the 1959 agreement unified them.
Used today. In the US the inch measures lumber, tools, fasteners, rainfall and personal height. Internationally it survives in screen sizes, smartphone displays, wheel rims, plumbing threads and the 3.5 inch and 2.5 inch drive formats in computers.
A centimeter is 0.01 meter, or 10 millimeters. One inch contains exactly 2.54 of them.
Origin. The metric system introduced in France in 1795 created the centimeter as a convenient hand-scale unit between the millimeter and the decimeter.
Used today. Centimeters are used for body measurements, clothing, paper and furniture almost everywhere outside the US. Doctors worldwide record height and head circumference in centimeters.
Exactly 30.48 cm, because a foot is 12 inches and 12 × 2.54 = 30.48.
6 feet is 72 inches, and 72 × 2.54 = 182.88 cm.
15.6 × 2.54 = 39.62 cm measured diagonally across the screen.
Roughly. The tyre's outside diameter is around 29 inches (73.7 cm), but the rim itself is the ISO 622 mm size, the same as a 700c road wheel.