cm to in Converter
Turn centimetre measurements into inches
cm to in FAQ
How do you convert centimetres to inches exactly?
The relationship between centimetres and inches is fixed: 1 inch = 2.54 centimetres exactly. To convert cm to in, you divide by 2.54: in = cm ÷ 2.54. For example, 180 cm ÷ 2.54 ≈ 70.87 in and 100 cm ÷ 2.54 ≈ 39.37 in. This calculator applies the exact formula so you do not have to re-do the division for each measurement.
Why do we divide by 2.54 and not use another number?
The inch is internationally defined as exactly 2.54 centimetres. That means every inch anywhere in the world is tied to the metric system through that one precise value. Going from inches to centimetres uses cm = in × 2.54, and going back from centimetres to inches uses in = cm ÷ 2.54. This converter follows that official definition, so your results match printed size charts, technical drawings and manufacturing specs.
Where are centimetres used vs inches?
Centimetres (cm) are standard across most of the world for body measurements, school work, product specs, furniture and room dimensions. Inches (in) remain common in the United States, parts of Canada and the UK for heights, clothing sizes, screens, tools and building materials. Converting cm to inches helps you interpret metric sizing when you are buying products that use inch units or comparing to US-focused size charts.
Is this converter accurate enough for clothing and furniture?
Yes. Because the 2.54 cm per inch relationship is defined exactly, any cm to in conversion based on it is as accurate as a printed table. For heights and clothing, you will usually round to one or two decimal places in inches. For furniture, monitors and home projects, you might round to the nearest quarter-inch or whole inch after converting. This tool gives you a precise inch value that you can round however your project requires.
How many decimal places of inches should I keep?
It depends on what you are doing:
- Human height — usually round to the nearest 0.5 or 0.25 in, or even whole inches.
- Clothing and tailoring — one decimal place or fractions like ⅛, ¼, ½ in.
- Furniture and DIY — nearest ⅛ or ¼ in is often enough.
This converter keeps full precision internally, then prints a clean inch value that you can round to your preferred level of detail.
Can I use this for monitor sizes and product specs?
Definitely. Many screens, monitors and product listings are marketed using inches, even when technical specs are in metric. If you know the dimension in centimetres from a drawing or spec sheet, this cm to in converter lets you see the equivalent in inches so you can compare with other products, reviews or store listings more easily.
What if my measurement starts in inches, feet or metres instead?
If you already have inches and want centimetres, you can switch to the in to cm tool via the “Swap Units” button. For other units such as feet or metres, the length conversion calculator gives you a single place to move between multiple length units without doing intermediate conversions by hand.
From metric centimetres to familiar inch values
This cm to in converter is built for those times when your tape measure, pattern or spec sheet gives you centimetres, but you need to think in inches. That might be human heights, clothing sizes, furniture dimensions, monitor diagonals or product specs. Instead of dividing by 2.54 on a calculator over and over, you enter the centimetre value once and get a line such as “180 cm ≈ 70.87 in”.
1. One centimetre input, one inch result
The layout stays deliberately minimal: a single input box for cm and a result card underneath. You can enter small sizes (for accessories or hardware), medium sizes (for clothes and body measurements) or larger dimensions (for furniture and screens). Behind the scenes, the converter divides by 2.54 exactly and formats the inch result so that it is easy to read on phones, tablets and desktop screens.
If you later need to reverse the process, from inches back to centimetres, the “Swap Units” button takes you directly to the in to cm page. The two tools work as a pair so you can move between metric and US-style length units without memorising or re-deriving formulas.
2. Simple linear relationship between cm and inches
The relationship between centimetres and inches is linear: doubling the centimetres doubles the inches. The only difference is the fixed scale factor:
- 1 in = 2.54 cm
- 1 cm ≈ 0.3937 in
From this you get the conversion pair cm = in × 2.54 and in = cm ÷ 2.54. For quick mental estimates people sometimes use 2.5 instead of 2.54, or say “about 2.5 cm per inch”. That can be fine for rough checks, but this converter uses the exact factor so your numbers match published charts, CAD drawings and official documents.
When you need to go beyond cm and inches to include feet, metres or millimetres, the length conversion calculator acts as a hub that keeps several length units in sync on one page.
3. Common cm to in values at a glance
These example conversions match what the calculator outputs and help you build intuition for how typical centimetre values translate into inches:
| Centimetres (cm) | Inches (in) |
|---|---|
| 50 cm | ≈ 19.69 in |
| 80 cm | ≈ 31.50 in |
| 100 cm | ≈ 39.37 in |
| 120 cm | ≈ 47.24 in |
| 150 cm | ≈ 59.06 in |
| 160 cm | ≈ 62.99 in |
| 170 cm | ≈ 66.93 in |
| 180 cm | ≈ 70.87 in |
A quick mental rule is to divide by 2 and add a little. For example, 160 cm ÷ 2 = 80; subtract about 10% (8) to land near 72 in; the exact value is ≈ 62.99 in, so you can refine the shortcut with practice. When you need precise numbers for cutting material, drafting patterns or filling in official forms, this converter uses the full 2.54 factor so your conversions stay consistent and reproducible.
4. Where the cm to in converter shines
You will most often reach for this tool in situations like:
- Heights and clothing sizes — translating metric height and body measurements into inches for size charts and forms.
- Furniture and interior layouts — converting metric dimensions from European catalogues into inches for US-based plans.
- Monitors, TVs and devices — turning centimetre diagonals or widths into inches to compare with marketing specs.
- DIY and home projects — matching metric tape-measure readings to inch-based tools, guides and hardware.
- Homework and teaching — double-checking manual cm-to-in conversions in maths and science exercises.
Because it follows the official relationship between centimetres and inches, you can come back to this cm to in converter any time you need reliable, repeatable length conversions between metric and US-style units.
References and further reading on length units
These references explain how centimetres and inches are defined and used:
- Centimetre — describes the centimetre as a metric unit of length and its relationship to metres and millimetres.
- Inch — covers the history of the inch, the international definition and common usage in different countries.
- NIST: Metric units and prefixes — provides official background on metric length units and conversions used in science, engineering and trade.
For critical construction, manufacturing or regulatory work, always follow your organisation’s official conversion and rounding procedures when moving between centimetres, inches and other length units.