Where inches-to-cm actually matters
Three situations keep coming up. The first is mounting: brackets, TV arms, monitor stands, and wall plates are usually specified in inches in the US and millimeters in Europe, so the conversion has to be exact or the holes will not line up. The second is cutting: US lumber and plywood are sold in inch thicknesses and foot lengths, but metric drawings and European hardware assume centimeters and millimeters. The third is sizing: clothing, shoes, and screens are quoted in inches in the US and centimeters almost everywhere else, which is why so many people search for height and waist conversions by name. The inch itself is still the standard unit in the US, Canada, and the UK for screen sizes, wheel diameters, pipe threads, and drill bits — even in countries that otherwise use metric for everything.
- • Use in For: US lumber and plywood sheets, VESA mount specs for TVs and monitors, US drill bit sizes, US clothing and shoe sizes, Screen sizes for TVs, monitors, laptops, and phones, US pipe and fastener specs
- • Use cm For: Metric construction drawings, European fasteners and anchors, EU furniture assembly, Metric sewing and tailoring, Metric height and waist measurements, Metric drill and bore sizes
Rule of Thumb: If you are going to drill it, cut it, or mount it, use the exact factor. If you are only estimating whether something fits in a room, 2.5 is fine.
Inches to Centimeters Conversion Formula — How to Convert in to cm
centimeters = inches × 2.54
Reverse: inches = centimeters ÷ 2.54 (or × 0.3937)
Step-by-Step in to cm Conversion Examples:
- •A VESA 100 mount hole spacing (4 in):4 × 2.54 =10.16 cm
- •A one-foot ruler:12 × 2.54 =30.48 cm
- •A 32-inch waist:32 × 2.54 =81.28 cm
- •A 32-inch TV or monitor:32 × 2.54 =81.28 cm
- •A 6-inch phone screen:6 × 2.54 =15.24 cm
- •Five feet three inches (63 in):63 × 2.54 =160.02 cm
Why the Inches to Centimeters Conversion Works & Common in to cm Converter Mistakes to Avoid
The factor is not arbitrary. Since 1959 the international inch has been defined as exactly 25.4 millimeters, which makes it exactly 2.54 centimeters by definition — not a measurement, a legal definition agreed between the US, UK, Canada, Australia, New Zealand, and South Africa. Before that agreement the inch drifted between standards: at various points it was based on the width of three barleycorns placed end to end, the width of a human thumb averaged across three thumbs, and 1/36 of a yard that itself varied by country. The 1959 agreement ended all of that. So when someone tells you the conversion is approximate, they are wrong. The only approximation on this page is the mental shortcut in the alternate formula, and that one comes with a warning.
The Common in to cm Converter Mistake: Rounding 2.54 down to 2.5 while working. It looks harmless, until you apply it to a real cut or a real hole. On a 4-inch hole spacing the error is 1.6 mm, which is enough to make a screw miss its anchor. On a 36-inch cut it is 1.44 cm, which is a visible gap in a joint. The second mistake is assuming a 100 mm VESA pattern equals 4 inches. It does not. 4 inches is 101.6 mm — 1.6 mm larger — and that difference will stop a bracket from seating. Third mistake: converting feet to centimeters without going through inches first. There are 12 inches in a foot, so 5 ft 3 in is 63 inches, not 5.3 inches. That one costs people an entire foot of height.
Inches to Centimeters Real-World Size Comparison Table
These are the conversions that come up again and again when you are reading a US spec sheet and working in metric. If you only memorise seven numbers, memorise these.
| Inches (in) | Centimeters (cm) | Real-World Size Benchmark |
|---|---|---|
| 1 in | 2.54 cm | Exactly one inch — the base unit |
| 4 in | 10.16 cm | VESA 100 hole spacing (100 mm) |
| 12 in | 30.48 cm | One foot — the standard ruler |
| 24 in | 60.96 cm | Two feet — a short shelf or monitor |
| 36 in | 91.44 cm | One yard — fabric and timber |
| 60 in | 152.4 cm | Five feet — counter height |
| 72 in | 182.88 cm | Six feet — a tall person |
in to cm Converter in Spreadsheets — Spreadsheet Shortcut (Excel & Google Sheets)
For inches to centimeters, put =A1*2.54 in the next cell. For the reverse, =A1/2.54. Excel and Google Sheets both also accept =CONVERT(A1, "in", "cm"), which is cleaner if you are converting between many different units in the same sheet. If your source data is formatted as text with a quote mark — like 12" — strip the quote first with =SUBSTITUTE(A1, "\"", "") before multiplying.
Inches to Centimeters Conversion — Frequently Asked Questions
How do I convert inches to centimeters?
Multiply the number of inches by 2.54. For example, 10 inches × 2.54 = 25.4 cm. The factor is exact, so you can trust as many decimal places as your input has.
What is 1 inch in centimeters?
Exactly 2.54 cm. This has been the international standard since 1959, when the inch was defined as 25.4 millimeters.
How many cm in an inch?
2.54 cm in one inch. To go the other way, one centimeter equals 0.3937 inches, which is 1 divided by 2.54.
How do I convert feet and inches to centimeters?
Convert feet to inches first (multiply by 12), add the remaining inches, then multiply the total by 2.54. Example: 5 ft 3 in = (5 × 12) + 3 = 63 inches, then 63 × 2.54 = 160.02 cm.
Is 178 cm 5'10"?
Yes, very nearly. 5'10" is 70 inches, and 70 × 2.54 = 177.8 cm. So 178 cm rounds to 5'10", and the two are within 2 millimetres of each other.
What is 37 cm in inches?
37 ÷ 2.54 = 14.57 inches, or roughly 14 and a half inches.
How tall is 5 ft 3 in centimeters?
5 ft 3 in is 63 inches total. 63 × 2.54 = 160.02 cm, so just over 160 cm.
What is 6 inches in centimeters?
6 × 2.54 = 15.24 cm. That is about the diagonal of a large phone screen.
What is 12 inches in centimeters?
12 × 2.54 = 30.48 cm. Twelve inches is one foot, so one foot is 30.48 cm exactly.
Is a 100 mm VESA pattern the same as 4 inches?
No. 4 inches is 101.6 mm, which is 1.6 mm larger than 100 mm. That gap is enough to stop a bracket seating properly, so never treat the two as interchangeable.
How do I convert fractional inches to centimeters?
Turn the fraction into a decimal first, then multiply by 2.54. For example, 3 1/2 inches is 3.5 inches, and 3.5 × 2.54 = 8.89 cm. For 1/4 inch: 0.25 × 2.54 = 0.635 cm.
How do I convert inches to centimeters in Excel or Google Sheets?
Multiply the cell by 2.54: =A1*2.54. To go back, use =A1/2.54. Excel also has a built-in function: =CONVERT(A1, "in", "cm").
What is the relationship between inches and centimeters?
A fixed ratio. One inch always equals exactly 2.54 centimeters, with no rounding and no variation by country since 1959.
How many centimeters is a 32-inch screen?
32 × 2.54 = 81.28 cm. That is the diagonal measurement, which is how screens are always specified.
in to cm Quick-Reference Conversion Table
The conversions that come up most often in mounting, cutting, drilling, and sizing work.
| To convert | Operation | Example |
|---|---|---|
| in → cm | × 2.54 | 10 in → 25.4 cm |
| cm → in | ÷ 2.54 | 25.4 cm → 10 in |
| in → mm | × 25.4 | 4 in → 101.6 mm |
| mm → in | ÷ 25.4 | 100 mm → 3.94 in |
| ft → in | × 12 | 5 ft → 60 in |
| ft → cm | × 30.48 | 5 ft → 152.4 cm |
| cm → mm | × 10 | 2.54 cm → 25.4 mm |
| in → ft | ÷ 12 | 36 in → 3 ft |