Convert Inch to Centimetre

Quick answer: Inch to Centimetre

1 Inch = 2.54 Centimetre (in → cm). To convert inch to centimetre, multiply by 2.54. To convert centimetre to inch, multiply by 0.3937008. The converter at the top does this instantly and both ways; the sections below give the formula, worked examples, a full conversion chart and answers to the most common inch-to-centimetre questions.

How to convert Inch to Centimetre

To convert inch to centimetre, multiply the number of inch by the conversion factor 2.54, because 1 in = 2.54 cm. The conversion is linear, so the same factor works for any value — whole numbers, decimals or fractions. For the reverse direction, 1 cm = 0.3937008 in, so you divide by 2.54 (or multiply by 0.3937008) to turn centimetre back into inch.

cm = in × 2.54  ·  in = cm × 0.3937008

1. Write down the value you want to convert, in inch.
2. Multiply it by 2.54.
3. The result is the same area/length/quantity expressed in centimetre.

Inch to Centimetre — worked examples

Each row shows the exact arithmetic so you can follow the conversion step by step. For example, 5 inch is 12.7 centimetre because 5 in × 2.54 = 12.7 cm.

Common Inch to Centimetre conversions

These are the inch-to-centimetre values people look up most often. Every figure is computed from the exact factor, so you can rely on them for quick reference:

• 1 inch = 2.54 centimetre
• 2 inch = 5.08 centimetre
• 2.5 inch = 6.35 centimetre
• 3 inch = 7.62 centimetre
• 4 inch = 10.16 centimetre
• 5 inch = 12.7 centimetre
• 6 inch = 15.24 centimetre
• 7 inch = 17.78 centimetre
• 8 inch = 20.32 centimetre
• 9 inch = 22.86 centimetre
• 10 inch = 25.4 centimetre
• 12 inch = 30.48 centimetre
• 15 inch = 38.1 centimetre
• 20 inch = 50.8 centimetre
• 25 inch = 63.5 centimetre
• 30 inch = 76.2 centimetre
• 50 inch = 127 centimetre
• 75 inch = 190.5 centimetre
• 100 inch = 254 centimetre
• 200 inch = 508 centimetre
• 500 inch = 1,270 centimetre
• 1000 inch = 2,540 centimetre

Inch to Centimetre conversion chart (both directions)

The chart below converts inch to centimetre and centimetre to inch side by side, so it works whichever way you need. 1 inch = 2.54 centimetre, and 1 centimetre = 0.3937008 inch.

Inch vs Centimetre: which is bigger?

A inch is the larger unit: one inch equals 2.54 centimetres. Put another way, you need 2.54 centimetres to make a single inch.

What is a Inch? History, origin and usage

The inch takes its name from the Latin uncia, 'a twelfth part', because it was one-twelfth of a Roman foot, the same root that gave English the word 'ounce'. It was also understood as the width of a man's thumb, and one medieval English rule averaged the thumb-breadths of three different men.

The inch is used in the US, UK and Canada for screen sizes, paper, body measurements and countless engineering contexts. Since 1959 it is defined as exactly 2.54 centimetres.

An old English statute defined the inch as three barleycorns laid end to end, a standard that even shaped shoe sizing. Screen, tyre and wheel sizes are still quoted in inches almost everywhere in the world.

What is a Centimetre? History, origin and usage

The centimetre is one-hundredth of a metre, from the Latin centum, 'hundred'. It became prominent as the base length of the centimetre-gram-second (CGS) system used by many 19th- and early-20th-century physicists.

The centimetre is the everyday metric unit for small measurements such as human height, clothing sizes, paper and rulers across most of the world. It sits conveniently between the millimetre and the metre.

For decades scientists worked in the centimetre-gram-second system before the metre-kilogram-second system prevailed. A standard school ruler is typically 30 cm long.

Convert 1 Inch to other units

It can help to see a inch next to the other units it is commonly compared with. One inch (in) is equal to:

Convert 1 Centimetre to other units

One centimetre (cm) is equal to:

Tips for converting Inch to Centimetre

• To go from inch to centimetre, multiply by 2.54; to go back, divide by 2.54 (or multiply by 0.3937008).
• For a quick mental estimate, remember that 1 inch ≈ 2.54 centimetre, so 10 inch ≈ 25.4 centimetre.
• The converter above keeps full precision; the tables round for readability, so use the tool for exact figures.
• Both fields update live as you type — change either side to convert in that direction.

How to use this Inch to Centimetre converter

Type a number into the Inch field and the equivalent in Centimetre appears instantly — there is no “convert” button to press and nothing is sent to a server, so it works offline once the page has loaded and is safe for any data. You can also type into the Centimetre field to convert the other way (centimetre to inch). Use the swap control to flip the two units, and copy the result with a single click. Because the calculation runs in your browser with full floating-point precision, the converter is more exact than the rounded figures shown in the reference chart above — use the chart for quick look-ups and the tool for precise work.

Accuracy and method

Every figure on this page — the formula, the worked examples, the conversion chart and the “convert to other units” tables — is computed from a single verified conversion factor (1 in = 2.54 cm), never copied from a hand-typed lookup table that could drift. That factor is derived from each unit’s definition in terms of a common base unit, and an automated check re-verifies all of the site’s factors on every update, so the numbers here stay correct over time. This matters for inch-to-centimetre conversions because a small rounding error in a published table compounds quickly at larger quantities; computing from the exact factor avoids that.

Sources

• NIST Special Publication 811 — Guide for the Use of the SI — publishes the exact metric equivalents of the customary units. The inch, foot, yard and mile are defined exactly in metres by the 1959 international yard-and-pound agreement, so every imperial figure on this page is exact, not rounded.
• BIPM — The International System of Units (SI Brochure) — the defining document for the SI, published by the International Bureau of Weights and Measures. It fixes the base unit that this conversion resolves to, which is why the factor here can be exact rather than approximate.

The metric units (km, m, cm, mm, µm) are exact by definition, and the imperial units (mile, yard, foot, inch, nautical mile) use their exact international values. Traditional units (hand, span, finger, cubit, rod/pole, link, rope, ken, league) are given at their commonly accepted standard sizes — historical local values sometimes differed, so confirm against a primary source before relying on them for legal or historical work.

Frequently asked questions

How many centimetre are in 1 inch?

1 inch = 2.54 centimetre (cm). To convert any number of inch to centimetre, multiply by 2.54.

How do I convert inch to centimetre?

Multiply the number of inch by 2.54. For example, 10 inch = 10 × 2.54 = 25.4 centimetre, and 25 inch = 63.5 centimetre.

How many inch are in 1 centimetre?

1 centimetre = 0.3937008 inch. So to convert centimetre back to inch, multiply by 0.3937008.

What is the formula to convert inch to centimetre?

centimetre = inch × 2.54. The reverse formula is inch = centimetre × 0.3937008.

How much is 100 inch in centimetre?

100 inch = 254 centimetre. (And 1000 inch = 2,540 centimetre.)

Which is bigger, a inch or a centimetre?

A inch is larger: 1 inch = 2.54 centimetre.

Is this inch to centimetre converter accurate?

Yes — every value is computed from the exact 2.54 cm per in factor (not rounded look-up tables), and the factors are re-verified automatically on every update.

Can I convert centimetre to inch too?

Yes. The converter works both ways — enter a value in either field. 1 centimetre = 0.3937008 inch.

Related length conversions

• Centimetre to Inch
• Finger to Centimetre
• Hand to Inch
• Centimetre to Kilometre
• Metre to Inch
• Astronomical Unit to Centimetre
• Pole to Centimetre
• Inch to Foot
• Rope to Centimetre
• Point to Inch

See all length conversions →