Convert Centimeters to Inches
Convert metric centimeter measurements into inches for clothing sizes, screen dimensions, height comparisons or shipping cartons.
1 cm = 0.393701 in
One centimetre equals exactly 0.393701 inches, because an inch is defined as precisely 2.54 cm. To convert centimetres to inches, divide by 2.54 — so 30 cm = 11.81 in and 100 cm = 39.37 in. The definition is exact by international agreement, which means the conversion introduces no measurement error of its own. The everyday use is height: 170 cm is 66.9 in, or 5 ft 7 in, and the two-step conversion trips people up because the remainder after dividing by twelve is inches, not a decimal fraction of a foot. So 5.6 ft is 5 ft 7 in, not 5 ft 6 in. Useful anchors: a credit card is 8.56 cm long, A4 paper is 21 cm wide, and a US Letter sheet is 21.6 cm — close enough to look identical and far enough apart to break a print layout.
Quick reference: centimeters to inches
| Centimeters | Inches |
|---|---|
| 1 | 0.394 in |
| 2.54 | 1 in (exact) |
| 10 | 3.937 in |
| 20 | 7.874 in |
| 30 | 11.811 in |
| 50 | 19.685 in |
| 100 | 39.370 in |
| 170 | 66.929 in (5 ft 6.9 in) |
| 180 | 70.866 in (5 ft 10.9 in) |
How do you convert centimeters to inches?
Formula: inches = centimetres ÷ 2.54 • A person 170 cm tall → 170 ÷ 2.54 = 66.93 in, which is 5 feet 6.9 inches. • A 90 cm waist measurement on a European garment tag → 90 ÷ 2.54 = 35.43 in, so a US 36 waist is the closest standard size. • A 15 cm phone screen diagonal → 15 ÷ 2.54 = 5.91 in, matching a phone marketed as a 5.9-inch display.
When and why people use centimeters to inches
Clothing is the most common reason people convert. European and Asian garment labels give chest, waist and inseam in centimetres, while US and UK sizing uses inches, and the mismatch is why online orders so often arrive the wrong size. Converting the actual body measurement rather than trusting the size letter is far more reliable. Screens and displays are the second case. Televisions, monitors and phones are marketed by diagonal inches almost worldwide, even in countries that use metric for everything else, so a specification sheet quoting 68.6 cm is really describing a 27-inch monitor. Height comparison is the third. Converting a metric height into feet and inches needs two steps: divide by 2.54 to get total inches, then divide by 12 for whole feet and keep the remainder as inches. That second step is where most people go wrong, treating the decimal part of the feet figure as if it were inches directly.
Common mistakes to watch for when converting centimeters to inches
The biggest error is misreading the decimal in a feet-and-inches result. Dividing 170 cm by 2.54 gives 66.93 inches, and dividing that by 12 gives 5.577 feet — but the person is 5 feet 6.9 inches, not 5 feet 5.77 inches. The 0.577 is a fraction of a foot and has to be multiplied by 12 to become inches. A second mistake is using 2.5 instead of 2.54 as a shortcut; the 1.6% error means a 180 cm height comes out an inch and a half too tall. A third is assuming a garment's stated size corresponds to a body measurement — vanity sizing means a labelled 32-inch waist is frequently 34 inches of actual fabric.
How to estimate centimeters to inches in your head
Divide by 2.5 rather than 2.54 and then subtract about 1.5% of the result. For 100 cm: 100 ÷ 2.5 = 40, minus 0.6 gives 39.4 inches against a true 39.37. A faster approach for body heights is to memorise three anchors and interpolate: 150 cm is 4 ft 11, 165 cm is 5 ft 5, and 180 cm is 5 ft 11. Most heights people ask about fall between these, and each 2.5 cm is roughly one inch, so you can step up or down from the nearest anchor. For small measurements, remember that 10 cm is very close to 4 inches (3.94) and 30 cm is very close to a foot (11.81). Both are within 2%, which is fine for judging whether something fits a shelf and not fine for cutting material.
Centimeters to Inches FAQ
How many inches is 1 cm?
- 0.393701 inches. The inch is defined as exactly 2.54 cm, so the conversion is exact rather than approximate.
How do I turn centimetres into feet and inches?
- Divide by 2.54 for total inches, then divide by 12 for whole feet. Multiply the leftover decimal by 12 to get the remaining inches.
Why is my height conversion wrong?
- Almost always because the decimal part of the feet figure was read as inches. 5.577 feet is 5 feet 6.9 inches, not 5 feet 5.77 inches.
Is 2.5 close enough as a shortcut?
- It carries a 1.6% error. On a 180 cm height that is about an inch and a half — enough to matter for clothing or height.
How many cm is 5 feet 10 inches?
- 70 inches × 2.54 = 177.8 cm.
Why are screens sized in inches everywhere?
- Display sizing standardised on the diagonal inch early in the industry and stuck, even in fully metric markets. A 68.6 cm panel is simply a 27-inch monitor.
Does clothing size match my measurement?
- Often not. Vanity sizing means a labelled waist can be two inches larger than the number suggests, so convert your own measurement and compare against the brand's chart.
Is my input stored?
- No. Everything is calculated locally in your browser and nothing is uploaded.
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Sources: 1959 international yard and pound agreement defining the inch as exactly 2.54 cm; NIST Special Publication 811; ISO 3635 garment size designation.