What Is A5 Size in mm, cm and Inches?

A5 measures 148 by 210 millimetres, which converts to 14.8 by 21 centimetres or approximately 5.8 by 8.3 inches. It sits within the international A-series paper system, exactly half the size of A4 when folded along its longest edge.

Where does the A5 measurement come from?

The A-series paper system, used across the UK and most of the world, is built on a mathematical ratio that keeps every size proportionally identical when halved or doubled. Starting from A0, each smaller size is created by folding the previous sheet in half along its longest side, and A5 is the result of folding A4 once.

What does A5 look like in different units?

In millimetres, A5 is 148 by 210. In centimetres, that becomes 14.8 by 21. Converted to inches, the dimensions come out to roughly 5.8 by 8.3. Designers working across international software or with overseas clients sometimes need all three figures to hand, since default measurement units vary between design programs and regions.

Unit	Dimensions
Millimetres	148 x 210 mm
Centimetres	14.8 x 21 cm
Inches	5.8 x 8.3 in

How does A5 compare with other common sizes?

A5 is exactly half the area of A4 and exactly double the area of A6. This consistent relationship is what makes the A-series so practical for print production, since a printer producing A4 sheets can fold or cut them directly into A5 without wasting material, and the same logic applies moving between any two adjacent sizes in the series.

Why is A5 such a popular choice for printed materials?

A5 is large enough to hold a meaningful amount of text and imagery, yet small enough to remain compact and easy to distribute. This balance makes it a common choice for booklets, leaflets, invitations, greetings cards and event programmes, where a full A4 sheet would feel oversized but a smaller A6 card would not leave enough room for content.

Does A5 size affect how a document should be designed?

Yes. Margins, image placement and font sizing that work comfortably on A4 do not always translate directly to A5, since the reduced dimensions mean less space for the same amount of content. Designers typically simplify layouts, reduce margins slightly and choose font sizes that remain legible within the smaller page area.

What should you check before sending A5 artwork to print?

Confirming that your design software is set to the correct unit and that the page dimensions match 148 by 210 millimetres exactly avoids awkward last-minute resizing. It is also worth checking that bleed and safety margins have been added around this base size rather than included within it.

Read our full paper sizes guide for more on how A-series formats compare, or speak to Minuteman Press Ipswich about which size suits your next project.

Knowing the exact A5 dimensions in every unit makes it far easier to set up artwork correctly the first time.