Two exercise books sit side by side on the shelf. One looks like a sheet of printer paper folded in half. The other is a full page. Both say "exercise book" on the cover. The booklist just says "A4". A parent who grabs the wrong one ends up trimming worksheets to fit, or watching a child's handwriting cram into a page that is too small.

Size seems like a small detail next to ruling and binding. It is not. This guide compares A4 and A5 directly and explains when each one earns its place in a school bag. It sits inside our notebooks and paper for school guide, which covers the full buying decision.

Quick answer

A4 exercise books measure 297mm by 210mm. A5 exercise books measure 210mm by 148mm, which is exactly half an A4 sheet. A4 suits worksheets, diagrams and subjects with heavy written content. A5 suits portable note-taking, homework diaries and lighter subjects. A4 is commonly specified for many school subjects, but requirements vary between schools and year levels. Always check the booklist first. Always check your booklist first, since the school sets the size, not personal preference. Although this guide focuses on exercise book sizes, the same A4 and A5 dimensions also apply to many school notebooks and planners. 

A4 and A5, Measured and Compared

The numbers matter more than they seem to.

A5 is not a smaller version of A4 with the same proportions shrunk down evenly. It is literally one A4 sheet cut in half. That is why an A5 book always looks noticeably smaller, not just a little smaller, next to an A4 one.

Why the Booklist Decides the Size

Australian primary and secondary schools set their own stationery lists. Size, like ruling, is not left to preference. When a booklist specifies an A4 exercise book, follow that requirement rather than substituting an A5 book.

If the booklist does not specify a size, check with the teacher or school before buying. If the school allows a choice, A4 provides more space for worksheets, diagrams and longer written tasks, while A5 is easier to carry and suits lighter note-taking.

For the ruling that pairs with each size, see our guide to dotted thirds, 8mm and 14mm exercise book rulings.

When A4 Makes Sense

A4 is commonly used for schoolwork because it provides more space for worksheets, diagrams and longer written tasks. 

• Worksheets fit without trimming. Most handouts, printed activities and homework sheets are printed on A4 paper. A student can glue a full page into an A4 book without folding it.
• More room for diagrams. Science, geography and maths often need space for labelled diagrams, graphs or long working. A5 pages fill up fast for this kind of work.
• Fewer books per subject. A4 books hold more content per page, so a subject with heavy writing may need fewer books across the year.

Key note: A4 is heavier in a bag than A5, book for book. If your child carries several A4 books daily, weight becomes a real factor, covered further down.

Our A4 Math Grid Book 55gsm 7mm is a practical example. Its A4 format gives enough width for graphs and multi-step working, which a smaller page would cramp.

When A5 Makes Sense

A5 earns its place for a different set of tasks.

• Portability. A5 books fit into smaller bags and pencil cases, which matters for younger students or for a book that travels between home and school daily.
• Homework diaries and quick reference. Short daily entries do not need a full A4 page. A5 avoids wasted space.
• Lighter overall bag weight. A student carrying several books benefits from the lower weight of A5 pages, even though page count sometimes needs to be higher to hold the same content.

Our Bibbulmun Spiral Notebook A5 Ruled 7mm is built for this kind of use. At 300 pages, it holds a full year of notes in a compact, portable format, which suits students who are past early handwriting practice and need a book they can carry easily.

Size and School Bag Weight

Australian school-bag guidance commonly uses 10% of a student's body weight as a reference point. CHOICE notes that for a 40–50kg student, this would be around 4–5kg, including books, a laptop, lunchbox and other school items.

A4 books can add more bulk and weight to a school bag than comparable A5 books, depending on the page count, paper weight and binding.

Practical ways to manage this without ignoring the booklist:

• Check whether books can stay at school and only travel home when needed for homework.
• Avoid buying extra-thick books beyond what the booklist or subject actually needs. See our guide on how many exercise books a student needs per year for a practical count.
• Where the school allows some flexibility, such as for a personal reading journal or homework diary, A5 is the lighter choice.

Key note: If the school requires A4, use the specified size rather than switching to A5. To reduce unnecessary weight, check the total book count, avoid spare books that are not needed, and keep books at school when permitted.

Common Patterns by School Stage 

Booklists shift as students move through school, though patterns vary between schools and states.

These are general patterns rather than national requirements. School booklists and teacher instructions take priority. 

This is a general pattern seen across Australian schools, not a fixed national rule. Some schools run their own system entirely. The booklist for your specific school and year level is always the accurate source.

Ruling and Size Work Together

Size and ruling are two separate decisions, but they show up on the same booklist line. A booklist might read "A4, 8mm ruled, 96 pages", which is three separate specifications in one line item.

Getting the size right does not guarantee the ruling is right, and the reverse is also true. Check both details against the shelf label before buying. Our guide on exercise book rulings breaks down dotted thirds, 8mm, 14mm and Queensland ruled formats in detail.

Mixed-Size Booklists

Many families end up buying both sizes in one order. A typical mixed list might ask for:

• A4 exercise books for English, science, humanities and maths.
• An A5 homework diary or reading journal.
• An A5 or A4 notebook for a student's personal study notes, depending on the school's own preference.

There is nothing unusual about a mixed order. It reflects how differently sized books serve different jobs, rather than one size being generally superior.

A simple way to plan a mixed order is to sort the booklist by subject first, then check each line for both size and ruling before adding it to the cart. Group the A4 items together, then the A5 items. This makes it easier to spot a mistake, such as an A5 book listed for a subject that clearly needs diagram space, before it ends up in the shopping bag. It also helps when comparing prices or checking stock, since you are not switching between formats line by line.

A4 and A5 Exercise Book & Notebook at School Stationery Supplies

The details below come from live product pages in our Notebooks & Paper collection. Always check the current product page for ruling, page count and stock before ordering.

Common Mistakes When Choosing Size

• Buying A5 to save money when the book list specifies A4. Worksheets will not fit, and the book may not meet school requirements.
• Assuming size and ruling are the same decision. They are listed together but chosen separately.
• Overloading a bag with A4 books "just in case". Check the guide on quantities per year before adding extras.
• Ignoring bag weight guidance entirely. The 10 per cent rule from the Chiropractors' Association of Australia is a useful sanity check, not just advice for backpack shopping.
• Buying A5 for a subject with heavy diagram work. Maths and science usually need the extra width of A4.

Frequently Asked Questions

What is the difference between A4 and A5 exercise books?

A4 measures 297mm by 210mm. A5 measures 210mm by 148mm, exactly half of A4. A4 gives more writing space and fits standard worksheets. A5 is lighter and more portable.

Which size does my child need for school?

Check the schoolbook list first. Most Australian primary and secondary schools specify A4 for core subjects. A5 is more common for homework diaries or personal study notes, when the school allows a choice.

Is A5 too small for primary school?

Not necessarily, for the right task. A5 works well for a homework diary or a spelling book. For subjects with worksheets or diagrams, A4 usually suits better.

Does book size affect school bag weight?

Yes. A4 books are heavier and bulkier than A5 books. If bag weight is a concern, the Chiropractors' Association of Australia recommends keeping a packed bag under 10 per cent of a student's body weight, and reducing unnecessary extra books helps more than switching required A4 books to A5.

Can I use A5 instead of A4 if the booklist says A4?

Generally, no. A4 worksheets will not fit an A5 page without trimming or folding, and the book may not meet the teacher's expectations for the subject.

Choosing the Right Size From the Start

A4 and A5 both have a place in an Australian school bag. A4 handles worksheets, diagrams and heavier written subjects. A5 suits portable, lighter tasks like homework diaries and personal notes.

Start with the booklist, not the shelf. Where the school gives no size at all, A4 is the safer general default, with A5 kept for the lighter jobs it does well.

For the full picture on notebooks, paper and quantities, see our notebooks and paper for school guide. Ready to shop both sizes? Browse our Notebooks & Paper collection.

Supporting Articles in This Series

• Notebooks & Paper for School: The Complete Australian Buying Guide
• Dotted Thirds, 8mm, 14mm: Australian Exercise Book Rulings Explained
• What Does GSM Mean on School Paper? (And Why 70gsm Bleeds)
• How Many Exercise Books Does a Student Need Per Year?
• Stapled vs Spiral vs Wiro-Bound: Which Notebook Binding Lasts a Year?
• How to Cover School Books Without Bubbles (Contact vs Slip-On)
• 80gsm vs 100gsm Copy Paper: When the Heavier Ream Is Worth It
• Recycled Notebooks and Copy Paper: Do They Hold Up in the Classroom?
• Ream, Box or Pallet? Bulk Copy Paper Quantities Explained
• Why Your Printer Keeps Jamming (It's Usually the Paper)

About the Author: 

The School Stationery Supplies Team publishes practical buying guides for Australian students, parents and teachers. Visit School Stationery Supplies for notebooks, paper, pens and school essentials.

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