Cubic Inches to Cubic Centimetres

2.54 cubed

An inch is exactly 2.54 centimetres, and volume cubes the length factor. So a cubic inch is 2.54³ cubic centimetres — exactly 16.387064.

1 in³ = 2.54³ = 16.387064 cm³ exactly

American engine displacement is the classic use. A 350 small-block is 350 cubic inches, which is 5,735 cc, or 5.7 litres. A 427 is 7.0 litres.

Reaching for 2.54 instead of 16.387 gives an answer six and a half times too small, which is the standard error in cubic conversions.

The cubic inch

A cube one inch on each side, exactly 16.387064 millilitres. American engine sizes were quoted in cubic inches for decades — a 350 small-block is 350 in³, or 5.7 litres.

The factor is the inch factor cubed: 2.54³ = 16.387064 cm³, exactly.

The cubic centimetre

A cube one centimetre on each side, and exactly equal to one millilitre. Medicine tends to write cc, engineering writes cm³, and cookery writes mL, but all three are the same volume.

Engine displacement is the most familiar use: a 1,600 cc engine sweeps 1.6 litres.

The working, step by step

Every line updates with whatever you type above. The point is the method, which is the same for any pair of units in this family.

Copy the working

The same quantity, two different numbers

One physical amount, read off two scales. The tick marks do not line up, and the gap between them is the conversion factor made visible.

How much is that?

A number is easier to judge next to something familiar.

Your turn

Reading a method and being able to use it are different things. Answer within half a per cent and it counts as correct.

How to use this converter

1. Type into either box. The other side updates as you go; there is no button to press.
2. Swap the direction with the button between the boxes, carrying your value across.
3. Set the decimals if the default is more or less precision than you need.
4. Copy the answer with its unit, ready to paste.
5. Use the shortcut buttons for the values that come up most often.
6. Share the result. The address bar tracks what you type, so the link you copy opens on the same number.

Common uses and tips

Where cubic conversions come up

• Concrete, topsoil and aggregate, sold by the cubic yard in America and the cubic metre almost everywhere else.
• Engine displacement, historically in cubic inches in the United States and in cubic centimetres or litres elsewhere.
• Shipping and storage, where container and room volumes come in cubic feet or cubic metres.
• Gas meters, which read in cubic feet in some countries and cubic metres in others.

The trap: cubic factors are length factors cubed

A foot is 0.3048 metres. A cubic foot is not 0.3048 cubic metres — it is 0.3048 × 0.3048 × 0.3048, which is 0.028316846592.

The same logic runs everywhere. A yard is 3 feet, so a cubic yard is 27 cubic feet. A metre is 100 cm, so a cubic metre is 1,000,000 cubic centimetres. Using the plain length factor instead gives an answer wrong by a factor of hundreds or thousands, which is at least an obvious sort of wrong.

Numbers worth carrying

• 1 m³ = 1,000 litres. Exactly.
• 1 ft³ = 28.3168 litres, or 1,728 cubic inches.
• 1 yd³ = 27 ft³, exactly.
• 1 in³ = 16.387064 mL, exactly.
• A cubic metre of water weighs a tonne; a cubic foot weighs about 62.4 lb.

Values people look up most

Each one opens the converter with the number already in it.

• 1 in³ to cm³
• 5 in³ to cm³
• 10 in³ to cm³
• 50 in³ to cm³
• 100 in³ to cm³
• 122 in³ to cm³
• 200 in³ to cm³
• 302 in³ to cm³
• 350 in³ to cm³
• 383 in³ to cm³
• 427 in³ to cm³
• 454 in³ to cm³
• 500 in³ to cm³
• 1,000 in³ to cm³

Quick reference

Cubic inches	Cubic centimetres
1 in³	16.387064 cm³
10 in³	163.87064 cm³
100 in³	1,638.7064 cm³
122 in³	1,999.221808 cm³
350 in³	5,735.4724 cm³
427 in³	6,997.276328 cm³
1,000 in³	16,387.064 cm³

Questions people ask

How many cc in a cubic inch?

16.387064, exactly.

What is a 350 cubic inch engine in litres?

5.7 litres.

Why is the factor not 2.54?

Because volume is three-dimensional. The factor is 2.54 cubed.