iCIndiaCalculators .org Verified 29 October 2026
All calculators Unit Converters Exams FAQs About
Home › Unit Converters › inches to cm converter
Unit Converters

Inches to centimetres calculator

Turn inches into centimetres and millimetres — useful for TV sizes, photo frames, fittings and any import spec that is written in inches.

Last verified 29 October 2026 Sources 2 No sign-up, no storage Formula and sources shown
Your numbers

No sign-up, no storage. Everything is calculated in your browser — nothing you type is sent anywhere. Change any input and press Calculate again.

Checked, not guessed.2 sources, 4 build tests and a changelog are on this page.
Your result
Enable JavaScript to see your result here. The method, formula and reference table below still explain the answer.
The method

How it is calculated

The formula this page actually runs

The inch is a defined multiple of the centimetre, not a separate measurement. That is why there is no lookup table needed — every value comes from multiplying by 2.54.

Formula centimetres = inches × 2.54 · millimetres = inches × 25.4
01

Use the exact inch

The international inch has been exactly 2.54 cm since 1959. Twelve inches make a foot, so 12 in = 30.48 cm and 36 in = 91.44 cm.

02

Multiply once

Any length in inches becomes centimetres by multiplying by 2.54. A 32-inch screen diagonal is 32 × 2.54 = 81.28 cm, which is how the box will describe it in metric markets.

03

Switch to mm when the spec uses it

Tiles, pipes and appliance drawings are often dimensioned in millimetres. One inch is 25.4 mm, so multiply by 25.4 instead of 2.54. 12 inches is 304.8 mm.

The numbers

Inches to centimetres — screens and common lengths

Reference values, not hidden defaults
InchesCentimetresMillimetresWhat it usually is
1 in2.5425.4A single inch
6 in15.24152.4Half a foot
10 in25.40254A common tablet diagonal
12 in30.48304.8One foot
24 in60.96609.6Two feet
32 in81.28812.832-inch TV diagonal
36 in91.44914.4One yard
43 in109.221092.243-inch TV diagonal
50 in127.00127050-inch TV diagonal
55 in139.70139755-inch TV diagonal
65 in165.10165165-inch TV diagonal
Screen sizes are quoted as the diagonal in inches; the centimetre figure is that same diagonal, not the width or height of the panel. Lengths such as 12 in and 36 in convert like any other measurement.
Before you use it

What most pages get wrong

4 things worth knowing before you use the number
01 · The definition

An inch is exactly 2.54 cm

The 1959 international agreement fixed the inch at 2.54 cm, and every conversion on this page follows from that one number. A foot is 12 inches, so 30.48 cm; a yard is 36 inches, so 91.44 cm.

02 · Screen sizes

The inch figure is the diagonal, not the width

A 55-inch TV has a 139.7 cm diagonal. The panel is narrower than that, and the cabinet adds a little more again — so never treat the diagonal as the width of the wall gap you need.

03 · cm and mm

Millimetres are the unit on most Indian specs

Tile sizes, pipe diameters and appliance drawings in India are usually written in mm. One inch is 25.4 mm, so a 24-inch tile edge is 609.6 mm, not 600 mm.

04 · Mixed tapes

Read one edge of a two-unit tape

Indian tape measures often print inches on one edge and centimetres on the other. Reading one edge and converting once is safer than reading whichever edge is closer.

Questions

Frequently asked questions

The queries people actually search
How many centimetres is 1 inch?+
1 inch is exactly 2.54 cm, or 25.4 mm. That factor is a definition, so it does not vary with the material or the country.
What is a 32-inch TV in centimetres?+
A 32-inch TV has an 81.28 cm screen diagonal, because 32 × 2.54 = 81.28. The width and height depend on the aspect ratio and the bezel, so they are smaller than 81.28 cm.
How many cm is 12 inches?+
12 inches is 30.48 cm. Since 12 inches is one foot, that also confirms 1 ft = 30.48 cm.
How do I convert inches to cm by hand?+
Multiply the inches by 2.54. For a quick estimate, multiply by 2.5 and add a little: 32 × 2.5 = 80 cm, and the exact answer is 81.28 cm. Use 25.4 instead of 2.54 when the answer needs to be in mm.
Why are TV and monitor sizes quoted in inches?+
Screen sizes became a trade convention in inches and stayed that way worldwide, even in metric countries. The physical size is unchanged; the centimetre figure on this page is the same diagonal measured in cm.
Is a 1-inch pipe really one inch across?+
No. Nominal pipe sizes are trade names, not actual dimensions — the outside diameter of a 1-inch nominal pipe is larger than 25.4 mm, and the inside depends on the wall thickness. Measure the actual pipe rather than converting the nominal size.
How many inches is 170 cm?+
170 cm is 66.93 inches, or about 5 ft 7 in. Divide centimetres by 2.54 to get inches, then divide by 12 if you want feet.
Trust layer — how to check this page

Sources, dates and a changelog.

Every number this calculator uses is either an input you control or a value from the sources below. The formula is compiled and tested at build time, so the page cannot ship with a broken calculation.

Sources

This page

  • Last verified: 29 October 2026
  • Next review: 29 April 2027
  • Vertical: Unit Converters
  • Build tests: 4 passed
  • Changelog: 1 entry

How we handle errors

  • Spotted a mistake? Report it — we correct and log it.
  • Corrections appear in the changelog below.
  • Read the methodology and the disclaimer.
Changelog
2026-10-29First published with a screen-size table and the exact 2.54 cm factor.