A printable A4 versus A3 paper size cheat sheet for any office
An A3 sheet folded once gives you two A4 pages. That single relationship governs paper purchasing, finisher choice, scanner glass dimensions, and the price difference between an A4 and A3 office MFP. This cheat sheet covers everything else worth knowing on one printable page.
The single visual that explains the whole system
Every paper size in the A series follows the same rule: cut the next larger sheet in half along the long edge and the proportions stay the same. A0 cut in half gives two A1 sheets. A1 cut in half gives two A2. A2 cut in half gives two A3. A3 cut in half gives two A4. A4 cut in half gives two A5. The aspect ratio holds because each size is exactly the square root of two times the next smaller side.
The numbers worth memorising
Six dimensions cover every conversation a buyer or facilities team is likely to have about A4 and A3. Each appears below at the level of detail offices actually use, with rounded conversions where they help.
| Property | A4 | A3 | Notes |
|---|---|---|---|
| Dimensions | 210 × 297 mm | 297 × 420 mm | A3 is twice A4 by area. |
| Imperial approximation | 8.27 × 11.69 in | 11.69 × 16.54 in | Closest US match is letter or tabloid. |
| Weight of a single sheet at 80 gsm | 5 g | 10 g | Useful when shipping documents. |
| 500 sheet ream weight at 80 gsm | 2.5 kg | 5 kg | A3 ream takes twice the shelf space. |
| Average device width to handle the format | 460 to 500 mm | 580 to 640 mm | A3 MFP footprint is about 25% larger. |
| Typical price gap on similar devices | Baseline | +30 to +50% | A3 lease lines run roughly half again as much. |
When the format choice actually matters
For most offices the question of A4 only versus A3 capable resolves on three considerations. Each one is binary in practice: either it matters in your workflow or it does not.
Spreadsheets and tables that wrap badly on A4
Financial models, project schedules, drawing schedules and inventory reports rarely fit on A4 at readable font sizes. Offices that produce these regularly need A3 capability somewhere on the floor. A single A3 capable device, with the rest of the fleet at A4, usually covers the requirement.
Marketing collateral and presentation prints
A3 sized brochures, posters and signage are produced in house at marketing agencies, architecture practices and design studios. For these offices, A3 is core. For most other offices, A3 prints are infrequent enough to outsource to a local print shop without losing meaningful capability.
Architectural drawings and large schematics
A3 sits at the small end of the architecture drawing range. Most working drawings use A2 or A1, so a true architectural workflow needs a plotter rather than an A3 MFP. For preliminary drawings and meeting copies, however, A3 is enough.
Why an A3 device costs significantly more
The price gap between an A4 only MFP and an A3 capable one usually surprises buyers. Three engineering factors account for it. The paper path is longer and includes a wider drum and fuser, both of which carry premium components. The scanner glass and ADF must accommodate a wider sheet, which doubles the scanning area. The chassis is reinforced to support the additional weight of A3 paper trays. Together these factors lift list prices by 30 to 50% over the equivalent A4 device.
Format conversion rules of thumb
The arithmetic relationship between sizes turns into operational shortcuts. Five rules cover most office conversions.
| Rule | Use case |
|---|---|
| Two A4 pages on one A3 sheet | Booklet printing, side by side comparison tables. |
| One A4 page scaled to A3 doubles every linear dimension | Useful for posters and presentations from existing A4 originals. |
| One A4 page scaled to A5 halves every linear dimension | Booklets, postcards, handouts. |
| Two A3 pages on one A2 sheet | Trade show banners, exhibition material. |
| A4 portrait fits in A3 landscape twice | The basis of most A3 booklet finishers. |
Paper weight conventions on A4 and A3
Both formats use the same gsm weights. The choice of weight changes the feel and the device handling rather than the size. Common weights and their applications follow.
| Weight (gsm) | Use | Notes |
|---|---|---|
| 70 to 75 | Internal drafts, recycled stock | Lower opacity; bleed through possible on duplex. |
| 80 | Standard office paper | The default in nearly every Spanish office. |
| 90 to 100 | Letterhead, correspondence | Heavier feel; better duplex opacity. |
| 120 to 160 | Brochures, marketing material | Most MFPs require the bypass tray. |
| 200 to 300 | Card stock, covers | Specialist trays or bypass with adjusted nip pressure. |
Sizes outside A4 and A3 worth recognising
Three additional formats appear regularly in offices and should be on a complete cheat sheet.
A5 at 148 × 210 mm
Half an A4 sheet. Used for note pads, postcards, in flight magazines, and the small print runs an office sometimes produces for internal meetings. Most A4 MFPs handle A5 from the bypass tray.
A6 at 105 × 148 mm
Half an A5 sheet. Postcards, flyers, business event tickets. Production requires careful tray setup; many office MFPs do not feed A6 reliably from main trays.
US letter at 216 × 279 mm
Slightly wider and shorter than A4. Common in documents from US suppliers. Most European MFPs handle US letter, but the layout differs enough from A4 to disrupt headers and footers in templates.
Printing the cheat sheet
Use the browser print function to produce a one page A4 version. The visual at the top renders as a single block. The tables print across two sections. Laminate the printed copy for durability if it lives next to the device.