Paper Sizes Chart: A0 To A6 And GSM Guide (2026)
Paper sizes come up all the time in office life: ordering paper, choosing a copier, setting up a print job or sending artwork to a printer. This page puts the numbers in one place. Everything here follows the international ISO 216 standard used across the UK and Europe, and you can download the full table as a CSV.
A paper sizes at a glance
| Size | Millimetres | Inches | Area (square metres) |
|---|---|---|---|
| A0 | 841 x 1189 | 33.1 x 46.8 | 1.0 |
| A1 | 594 x 841 | 23.4 x 33.1 | 0.5 |
| A2 | 420 x 594 | 16.5 x 23.4 | 0.25 |
| A3 | 297 x 420 | 11.7 x 16.5 | 0.125 |
| A4 | 210 x 297 | 8.3 x 11.7 | 0.0625 |
| A5 | 148 x 210 | 5.8 x 8.3 | 0.031 |
| A6 | 105 x 148 | 4.1 x 5.8 | 0.016 |
Download the paper sizes data as CSV
How A sizes work
The A series is built on one clever idea. A0 has an area of exactly one square metre, and every size below it is half the one above. Fold an A3 sheet in half and you get A4. Fold A4 and you get A5. Because every sheet keeps the same proportions, a ratio of 1 to the square root of 2, you can enlarge or reduce between sizes on a copier without anything being cut off or distorted.
That's why copiers have preset zoom buttons:
| From | To | Zoom |
|---|---|---|
| A4 | A3 | 141% |
| A3 | A4 | 71% |
| A4 | A5 | 71% |
| A5 | A4 | 141% |
| A3 | A5 | 50% |
How many sheets fit?
| Size | Sheets per A0 |
|---|---|
| A1 | 2 |
| A2 | 4 |
| A3 | 8 |
| A4 | 16 |
| A5 | 32 |
| A6 | 64 |
SRA sizes
SRA sizes are slightly larger sheets used by printers so they can print right to the edge and trim. If you print flyers with full bleed on a production copier, you might see these.
| Size | Millimetres |
|---|---|
| SRA3 | 320 x 450 |
| SRA4 | 225 x 320 |
Paper weights (GSM)
GSM means grams per square metre. The higher the number, the heavier and thicker the paper.
| GSM | Typical use |
|---|---|
| 70 to 80 | Everyday office printing and copying |
| 90 to 100 | Better quality letters and reports |
| 120 to 170 | Flyers, leaflets and brochures |
| 200 to 250 | Covers, postcards and light card |
| 300 and above | Business cards and heavy card |
80gsm is the standard UK office paper weight.
How much does paper weigh?
Because A4 is one sixteenth of a square metre, an A4 sheet of 80gsm paper weighs 5 grams. That makes the maths easy.
| Item | Weight at 80gsm |
|---|---|
| 1 sheet of A4 | 5g |
| 1 sheet of A3 | 10g |
| Ream of A4 (500 sheets) | 2.5kg |
| Box of 5 reams | 12.5kg |
What can an office copier handle?
Most office copiers print 60 to 80gsm paper from the main trays without any fuss. Heavier paper and card usually goes through the bypass tray, and many office machines can take card in the region of 220 to 300gsm from there. Always check your machine's spec sheet before printing on card, as the limits vary between models. A3 printing needs an A3 machine. Our A3 vs A4 photocopiers guide explains the difference.
US paper sizes
US Letter (8.5 x 11 inches, 216 x 279mm) is slightly wider and shorter than A4. If you receive documents from the US, your copier may ask for Letter paper. Set it to fit to A4 to avoid a paper jam or a cropped page.
Use this data
You're welcome to use these tables in your own work. A link back to PhotocopierCompare is appreciated.
Methodology
A series dimensions follow ISO 216. Inch figures are converted from millimetres and rounded to one decimal place. Areas are rounded. Sheet weights are calculated from area and GSM. Copier paper limits are typical ranges from manufacturer spec sheets and vary by model.
Envelope sizes
Copier and printer trays often take envelopes too. The common C and DL sizes match the A series.
| Envelope | Millimetres | Fits |
|---|---|---|
| C4 | 229 x 324 | A4 flat |
| C5 | 162 x 229 | A4 folded once, or A5 flat |
| C6 | 114 x 162 | A4 folded twice, or A6 flat |
| DL | 110 x 220 | A4 folded into thirds |
Print envelopes from the bypass tray and check your copier's spec sheet for supported sizes.
Choosing paper for your copier
For everyday copying, 80gsm paper from a known brand jams less than very cheap paper. Store reams flat in a dry place, because damp paper curls and causes jams. Fan the stack before loading. For double sided printing, slightly heavier 90gsm paper reduces show through. Thin 70gsm paper saves a little on cost and postage weight, but can feed poorly on some machines.
When printing on card, set the paper type on the machine to match. The copier then adjusts its fuser temperature and speed, which gives a cleaner finish and protects the machine. Recycled paper works well in modern copiers too, and most manufacturers approve it for everyday use.
FAQs
What size is A4 in mm?
210 x 297mm.
What size is A3?
297 x 420mm, twice the size of A4.
What GSM is normal printer paper?
80gsm is the standard UK office weight.
How much does a ream of A4 weigh?
About 2.5kg for 500 sheets of 80gsm.
What zoom turns A4 into A3?
141%.