in to cm Converter
Convert inch measurements into centimetres
in to cm FAQ
How do you convert inches to centimetres exactly?
The conversion is based on a fixed definition: 1 inch = 2.54 centimetres exactly. That means to convert in to cm you simply multiply by 2.54. For example, 10 in × 2.54 = 25.4 cm and 72 in × 2.54 = 182.88 cm. This converter applies the exact cm = in × 2.54 relationship so you get clean, repeatable results every time.
Why is 1 inch defined as exactly 2.54 cm?
Historically, different countries used slightly different inch lengths. To avoid confusion, an international agreement defined the international inch as exactly 2.54 centimetres. That fixed value is now used in engineering, manufacturing, clothing and everyday life. Because the inch is tied precisely to the metric system, you can trust that every conversion using 2.54 will match official tables and technical documentation.
Where are inches used vs centimetres?
Inches (in) are still common in the United States, Canada and the UK for things like heights, clothing sizes, screens, tools and lumber. Centimetres (cm) are part of the metric system and are used widely across the world for body measurements, product specs, furniture dimensions and school work. Converting inches to centimetres helps you interpret US sizing and product information in a metric environment.
Is this converter accurate enough for sewing, DIY and furniture?
Yes. Because the inch-to-centimetre relationship is defined exactly, the converter is as accurate as any printed conversion chart. For sewing and clothing you will usually round to one decimal place (for example, 38.5 in → 97.8 cm). For woodworking, DIY and furniture, one or two decimal places in cm is normally more than enough. You can always round the output to match your tape measure or pattern.
How many decimal places of cm should I use?
It depends on your project:
- Body measurements and clothing — 1 decimal place (e.g., 92.5 cm).
- Furniture and DIY — 1–2 decimal places, or even whole cm for rough sizing.
- Technical drawings or CAD — match the precision specified in the design (often 1–2 decimal places).
This converter keeps full precision internally and then prints a clean centimetre value that you can round as needed.
Can I use this for human height and clothing sizes?
Definitely. Many online shops list heights and garment measurements in inches only, while you might prefer cm. If you know your height in inches (for example, 5 ft 8 in = 68 in), you can convert it to centimetres instantly. The same applies to waist, chest, inseam and sleeve lengths. Using a reliable in-to-cm converter makes international sizing guides much easier to work with.
What if my starting measurement is in cm, ft or m instead?
If you already have centimetres and want inches, use the dedicated cm to in tool via the “Swap Units” button. For other units such as feet or metres, the length conversion calculator lets you move between multiple length units on a single page without doing intermediate conversions yourself.
From everyday inch measurements to clean centimetre values
This in to cm converter is designed for situations where you have measurements in inches but need them in centimetres. That might be body measurements for clothing, furniture dimensions, monitor sizes, tool lengths or lumber and trim. Instead of multiplying by 2.54 on a pocket calculator over and over, you enter the inch value once and get a line such as “10 in = 25.4 cm”.
1. One inch input, one centimetre result
The interface stays deliberately minimal: a single input box for inches and a result card underneath. You can enter small values (for jewellery, electronics or hardware), mid-range lengths (for body measurements and clothing) or large values (for shelves, countertops or TV screens). The converter multiplies by 2.54 exactly and formats the centimetre result so it is easy to scan on phones, tablets and desktop screens.
When you later need to go the other way, from centimetres back to inches, the “Swap Units” button takes you directly to the cm to in page. The two tools are built as a pair, so you can move between imperial and metric lengths without changing your workflow or remembering different formulas.
2. Simple linear relationship between inches and centimetres
The relationship between inches and centimetres is linear: if you double the inches, you double the centimetres. There is just one fixed scale factor: 1 in = 2.54 cm exactly. That means:
- cm = in × 2.54
- in = cm ÷ 2.54
Quick mental estimates might treat 2.5 as “close enough”, which gives 1 in ≈ 2.5 cm. This converter uses the full 2.54 factor so your numbers line up with sewing patterns, woodworking plans and official size charts.
When you need to connect inches and centimetres with other units such as feet, metres or millimetres, the length conversion calculator provides a broader hub that keeps several length units in sync on one page.
3. Common in to cm values at a glance
These example conversions match what the calculator outputs and help you build a feel for how inch measurements translate into centimetres:
| Inches (in) | Centimetres (cm) |
|---|---|
| 1 in | 2.54 cm |
| 2 in | 5.08 cm |
| 5 in | 12.7 cm |
| 10 in | 25.4 cm |
| 12 in | 30.48 cm (1 foot) |
| 20 in | 50.8 cm |
| 30 in | 76.2 cm |
| 40 in | 101.6 cm |
A quick mental rule is to multiply inches by 2.5 and then add a little. For example, 20 in → 20 × 2.5 = 50, then add a bit to get 50.8 cm. That is often close enough when you are just deciding whether something will roughly fit. When you need the exact value for cutting wood, ordering custom furniture or checking garment sizes, this converter uses the precise 2.54 factor so your measurements stay consistent and reproducible.
4. Where the in to cm converter shines
You will most often reach for this tool in situations like:
- Body measurements and clothing — converting inch-based size charts into centimetres for easier comparison.
- Furniture and interior design — turning inches from US product listings into cm for your floor plan or room layout.
- DIY and woodworking — matching inch-based tools or plans with a metric tape measure and cutting list.
- Online shopping — checking whether monitors, shelves or gadgets given in inches will fit spaces measured in cm.
- School and homework — double-checking manual in-to-cm conversions in maths and science exercises.
Because it follows the official relationship between inches and centimetres, you can rely on this in to cm converter whenever you need clear, repeatable results that bridge imperial and metric measurements.
References and further reading on length units
These references explain how inches and centimetres are defined and used:
- Inch — covers the history of the inch, the international definition and its use in different countries.
- Centimetre — describes the centimetre as a metric unit of length and its relationship to metres and millimetres.
- NIST: Metric units and prefixes — provides official background on metric length units and conversions used in science and engineering.
For critical construction, manufacturing or regulatory work, always follow your organisation’s official conversion and rounding procedures when moving between inches, centimetres and other length units.