# Inch vs. Cm: What's the Difference?

By Janet White || Published on February 18, 2024
An inch is a unit of length in the imperial system, equal to 1/12th of a foot, while a centimeter (cm) is a unit of length in the metric system, equal to 1/100th of a meter.

## Key Differences

An inch is a traditional unit of length in the imperial and United States customary systems, historically based on the width of a human thumb. A centimeter is a unit of length in the metric system, part of the International System of Units (SI), and is defined based on the meter.
The inch is widely used in the United States for many everyday measurements. Centimeters, on the other hand, are commonly used in most other countries and in scientific contexts worldwide due to the global adoption of the metric system.
One inch is equal to exactly 2.54 centimeters, a conversion derived from the international agreement on yard and pound. Centimeters offer a more precise measurement for small lengths and are often used in fields like medicine and engineering.
Inches are often represented with the symbol “in” or a double prime (“), whereas centimeters are denoted by “cm”. This symbol difference is crucial in various professional fields to avoid measurement errors.
Inches are subdivided into smaller units called fractions, which can be more complex to calculate. Centimeters, being part of the decimal-based metric system, are easily divided into millimeters, offering simpler and more accurate calculations.

## Comparison Chart

### System of Measurement

Imperial and U.S. Customary
Metric System

### Unit Relation

1/12th of a foot
1/100th of a meter

### Common Usage

Predominantly in the U.S.
Globally, except the U.S.

### Precision

Less precise, uses fractions
More precise, uses decimal system

“in” or “
“cm”

## Inch and Cm Definitions

#### Inch

Inches are represented with the symbol “in” or a double prime.
The new phone’s screen is 5 diagonally.

#### Cm

A centimeter is a unit of length in the metric system, equal to 1/100th of a meter.
The ruler is 30 cm long.

#### Inch

An inch is historically based on the width of a human thumb.
The gap must be at least an inch wide.

#### Cm

Cm is part of the International System of Units (SI).
The laboratory equipment is calibrated in centimeters.

#### Inch

Inch is used in the imperial and U.S. customary measurement systems.
He measured his height as 6 feet 2 inches.

#### Cm

Centimeters are commonly used globally for precise measurements.
Her artwork was carefully measured in centimeters.

#### Inch

An inch is a unit of length equal to 1/12th of a foot.
The board was cut to 8 inches in length.

#### Cm

Centimeters are easily divided into millimeters for accuracy.
The incision was exactly 5 cm in length.

#### Inch

Inches can be subdivided into fractions for smaller measurements.
Cut the fabric into 1/2-inch strips.

#### Cm

Centimeters are denoted by the symbol “cm”.
The width of the book is 15 cm.

#### Inch

A unit of length in the US Customary and British Imperial systems, equal to 1/12 of a foot (2.54 centimeters). See Table at measurement.

#### Cm

The abbreviation for centimeter.

#### Cm

The chemical symbol for the element curium.

#### Cm

A metric unit of length equal to one hundredth of a meter

#### Cm

A radioactive transuranic metallic element; produced by bombarding plutonium with helium nuclei

## FAQs

#### What is an inch?

An inch is a unit of length in the imperial and U.S. customary systems.

#### Is the inch used worldwide?

The inch is mainly used in the United States.

#### What is a centimeter?

A centimeter is a unit of length in the metric system.

#### Can you convert inches to centimeters?

Yes, inches can be converted to centimeters by multiplying by 2.54.

#### What fields commonly use inches?

Inches are commonly used in construction, manufacturing, and personal measurements in the U.S.

#### What are the applications of centimeters?

Centimeters are used in scientific, medical, and everyday measurements worldwide.

#### Are inches and centimeters interchangeable?

They are not directly interchangeable but can be converted between each other.

#### Where is the centimeter commonly used?

The centimeter is used globally, especially in countries using the metric system.

#### How is an inch symbolized?

An inch is symbolized as “in” or with a double prime symbol (").

#### How precise is an inch?

Inches are less precise compared to centimeters and often require fractions.

#### Are inches bigger than centimeters?

Yes, one inch is larger than one centimeter.

#### How many centimeters are there in an inch?

There are 2.54 centimeters in an inch.

#### Is the inch part of the metric system?

No, the inch is part of the imperial and U.S. customary systems.

#### Can inches be used for scientific measurements?

Inches are less common in scientific measurements, with centimeters preferred for precision.

#### Are centimeters used in the U.S.?

Centimeters are used in some contexts in the U.S., especially in scientific and medical fields.

#### Is the centimeter part of the imperial system?

No, the centimeter is part of the metric system.

#### Which is more commonly used globally, inches or centimeters?

Centimeters are more commonly used globally due to the widespread adoption of the metric system.

#### What is the symbol for centimeter?

The symbol for centimeter is “cm”.

#### Why are centimeters considered more precise?

Centimeters are more precise due to their smaller size and decimal system.

#### Do inches and centimeters measure the same thing?

Yes, both measure length but in different units.