The C Series Paper Sizes is the geometric mean of the areas of the A and B series sheets of the same number. For instance, the area of a C5 sheet is the geometric mean of the areas of an A5 sheet and a B5 sheet. The use of the geometric mean makes each step in size: C0, C1, C2, C3, C4, C5, C6, C7, C8, C9, C10, smaller than the previous one by the same factor. It is usually used for envelopes and is defined in ISO 269 and there are many other paper size standards conventions have existed at different times and in different countries worldwide.

The C Series Paper Sizes Standard folding one in half and rounding down to the nearest millimeter gives the next in the series. It is defined by divided by 2 or half the size of the previous paper in a larger dimension. It can be used for writing paper, cards, printing documents, envelopes, and also in applications such as Microsoft Office like Word or Excel.

## C0, C1, C2, C3, C4, C5, C6, C7, C8, C9, C10

### C0 Paper Sizes

The dimension of C0 Paper Sizes in mm, cm, inch:

• C0 Size in mm is 917 × 1297 millimeter.
• C0 Size in cm is 91.7 × 129.7 centimeter.
• C0 Size in inch is 36.1 × 51.1 inches.

### C1 Paper Sizes

The dimension of C1 Paper Sizes in mm, cm, inch:

• C1 Size in mm is 648 × 917 millimeter.
• C1 Size in cm is 64.8 × 91.7 centimeter.
• C1 Size in inch is 25.5 × 36.1 inches.

### C2 Paper Sizes

The dimension of C2 Paper Sizes in mm, cm, inch:

• C2 Size in mm is 458 × 648 millimeter.
• C2 Size in cm is 45.8 × 64.8 centimeter.
• C2 Size in inch is 18.0 × 25.5 inches.

### C3 Paper Sizes

The dimension of C3 Paper Sizes in mm, cm, inch:

• C3 Size in mm is 324 × 458 millimeter.
• C3 Size in cm is 32.4 × 45.8 centimeter.
• C3 Size in inch is 12.8 × 18 inches.

### C4 Paper Sizes

The dimension of C4 Paper Sizes in mm, cm, inch:

• C4 Size in mm is 229 × 324 millimeter.
• C4 Size in cm is 22.9 × 32.4 centimeter.
• C4 Size in inch is 9.02 × 12.8 inches.

### C5 Paper Sizes

The dimension of C5 Paper Sizes in mm, cm, inch:

• C5 Size in mm is 162 × 229 millimeter.
• C5 Size in cm is 16.2 × 22.9 centimeter.
• C5 Size in inch is 6.38 × 9.02 inches.

### C6 Paper Sizes

The dimension of C6 Paper Sizes in mm, cm, inch:

• C6 Size in mm is 114 × 162 millimeter.
• C6 Size in cm is 11.4 × 16.2 centimeter.
• C6 Size in inch is 4.49 × 6.38 inches.

### C7 Paper Sizes

The dimension of C7 Paper Sizes in mm, cm, inch:

• C7 Size in mm is 81 × 114 millimeter.
• C7 Size in cm is 8.1 × 11.4 centimeter.
• C7 Size in inch is 3.19 × 4.49 inches.

### C8 Paper Sizes

The dimension of C8 Paper Sizes in mm, cm, inch:

• C8 Size in mm is 57 × 81 millimeter.
• C8 Size in cm is 5.7 × 8.1 centimeter.
• C8 Size in inch is 2.24 × 3.19 inches.

### C9 Paper Sizes

The dimension of C9 Paper Sizes in mm, cm, inch:

• C9 Size in mm is 40 × 57 millimeter.
• C9 Size in cm is 4 × 5.7 centimeter.
• C9 Size in inch is 1.57 × 2.24 inches.

### C10 Paper Sizes

The dimensions of C10 Sizes in mm, cm, inch:

• C10 Size in mm is 28 × 40 millimeter.
• C10 Size in cm is 2.8 × 4 centimeter.
• C10 Size in inch is 1.10 × 1.57 inches.

## Table of C Series Paper Sizes

Here is a Table of C Series Paper Sizes in unit of measurements in mm, cm, inches.

C Series Paper Sizes
Sizemmcminch
C0917 × 129791.7 × 129.736.1 × 51.1
C1648 × 91764.8 × 91.725.5 × 36.1
C2458 × 64845.8 × 64.818.0 × 25.5
C3324 × 45832.4 × 45.812.8 × 18.0
C4229 × 32422.9 × 32.49.02 × 12.8
C5162 × 22916.2 × 22.96.38 × 9.02
C6114 × 16211.4 × 16.24.49 × 6.38
C781 × 1148.1 × 11.43.19 × 4.49
C857 × 815.7 × 8.12.24 × 3.19
C940 × 574.0 × 5.71.57 × 2.24
C1028 × 402.8 × 4.01.10 × 1.57

The tolerances specified in the standard are:

• ±1.5 mm for dimensions up to 150 mm,
• ±2.0 mm for dimensions in the range 150 to 600 mm, and
• ±3.0 mm for dimensions above 600 mm.

These are related to comparison between series A, B and C.

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