Here is a Table of The C Series Paper Sizes. These include C0, C1, C2, C3, C4, C5, C6, C7, C8, C9, and C10. Standard Dimensions or Length and Width of Paper in C Series in unit of measurements in mm (millimeter), cm (centimeter), and inch (inches).

ISO specifies international standard (ISO) paper sizes used in most countries in the world today, although not in Canada, the United States, Mexico, Colombia, or the Dominican Republic. The standard defines the “A” , “B” and “C” series of paper sizes, including A4, the most commonly available paper size worldwide.

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.

The C series is usually used for envelopes and is defined in ISO 269. The area of C series papers is the geometric mean of the areas of the A and B series papers of the same number, for instance, the area of a C4 paper is the geometric mean of the areas of an A4 paper and a B4 paper. This means that C4 is slightly larger than A4, and slightly smaller than B4. The practical usage of this is that a letter written on A4 paper fits inside a C4 envelope, and both A4 and C4 paper fits inside a B4 envelope.