Paper Size Converter (A4 in Pixels, mm, Inches)
Over 100 paper, card and poster sizes in mm, inches, points and pixels at any DPI.
Paper size
In every unit
| DPI | Pixels | Megapixels |
|---|
Bleed and safe margin
For print: the artwork canvas is the trim size plus bleed on every side; keep text inside the safe area.
Sizes at 300 DPI
ISO A series
ISO 216 · portrait · pixels at 300 DPI
| Size | mm | in | px @ 300 |
|---|
About the Paper Size Converter (A4 in Pixels, mm, Inches)
Look up any paper, card, envelope or poster size and see it in millimetres, centimetres, inches, points and pixels, in portrait or landscape. Pixels are worked out at 72, 96, 150, 300 or 600 DPI, or at any DPI you type — so you know that A4 at 300 DPI is 2480 × 3508 px before you start a design.
The list covers the ISO A0–A10, B0–B10 and C0–C10 series, DL envelopes, RA and SRA printing stock, US Letter, Legal and Tabloid, ANSI A–E and architectural drawing sizes, the Japanese JIS B series, photo prints, passport photos, business and ID cards, US envelopes and posters. Add a bleed and a safe margin to get the exact artwork canvas for print, and enter any custom size to convert it or find the standard size it matches.
How to use it
- Pick a size: select one of the quick buttons, search (for example “A4”, “visiting card” or “4x6”), choose from the list, or select Custom size and type your own.
- Choose Portrait or Landscape, and the DPI — 300 for print, 150 for large posters, 72 or 96 for screens — or type another DPI.
- Read the size in every unit and at every common DPI, and select Copy next to the one you need.
- For print artwork, enter the printer’s bleed and safe margin to get the canvas size (with bleed) and the area where text is safe.
Examples
A4, portrait, 300 DPI
2480 × 3508 px (210 × 297 mm, 8.27 × 11.69 in)
Letter, portrait, 300 DPI
2550 × 3300 px (8.5 × 11 in, 215.9 × 279.4 mm)
A4 in points
595.28 × 841.89 pt
PDF and PostScript measure pages in points: 1 pt = 1/72 in.
A4, bleed 3 mm, 300 DPI
Canvas 216 × 303 mm = 2551 × 3579 px
3.5 × 2 in card, bleed 0.125 in, 300 DPI
Canvas 3.75 × 2.25 in = 1125 × 675 px
Custom: 2480 × 3508 px at 300 DPI
Matches A4 (portrait)
Common uses
- Setting up a canvas in Photoshop, Canva, GIMP or Figma for an A4 flyer, a poster or a visiting card at 300 DPI.
- Checking whether an image has enough pixels to print sharply at a given size.
- Converting a PDF page size in points to millimetres or inches.
- Choosing an envelope that fits a folded A4 or Letter sheet.
How ISO paper sizes work
ISO 216 sizes all have the same shape, a width-to-height ratio of 1 : √2 (about 1 : 1.414). That is the only shape that keeps its proportions when a sheet is cut in half across its long side, so A3 cut in half gives two A4 sheets. A0 has an area of one square metre (841 × 1189 mm), and each next size halves the longer side, rounded down to a whole millimetre: A1 is 594 × 841, A2 420 × 594, down to A10 at 26 × 37 mm.
B sizes lie between the A sizes (B1 is between A0 and A1), for posters and books. C sizes (ISO 269) lie between A and B, so a C4 envelope holds an unfolded A4 sheet, C5 holds A4 folded once, and DL (110 × 220 mm) holds A4 folded in three. RA and SRA (ISO 217) are slightly larger sheets that printers trim down to A sizes. The Japanese JIS B series has 1.5 times the area of the A size, so JIS B5 (182 × 257 mm) is not the same as ISO B5 (176 × 250 mm).
Pixels, DPI and points
Pixels = inches × DPI = millimetres ÷ 25.4 × DPI, rounded to a whole pixel. 1 inch is exactly 25.4 mm and 72 points; CSS also defines 1 inch as 96 px, which is why 96 DPI gives the size of a page in a browser.
- 300 DPI is the usual target for printed photos, flyers and documents.
- 150 DPI is often enough for large posters seen from a distance.
- 72 DPI gives the size in points (PDF page sizes); 96 DPI gives CSS pixels.
The DPI number stored in an image file does not change its pixels: a 2480 × 3508 px image prints as A4 at 300 DPI, or as A3 at about 212 DPI.
Bleed and safe margin
Printers cut sheets after printing, and the blade can drift by a millimetre or so. Bleed is extra background beyond the trim line on every side, so colours run to the edge without white slivers — commonly 3 mm, or 1/8 in (3.175 mm) for US printers. The safe margin is a band inside the trim where you should not put text or logos, commonly 3–5 mm. The artwork canvas is the trim size plus twice the bleed; the safe area is the trim size minus twice the margin. Always use the values your printer asks for.
US, ANSI and architectural sizes
The US and Canada use Letter (8.5 × 11 in), Legal (8.5 × 14 in) and Tabloid (11 × 17 in; called Ledger when landscape). Engineering drawings use ANSI A–E (ANSI/ASME Y14.1): each size doubles the previous one, from A (8.5 × 11 in) to E (34 × 44 in). Architects use Arch A–E (9 × 12 in to 36 × 48 in), which alternate between 3:4 and 2:3 shapes; Arch E1 is 30 × 42 in.
Limitations
- Pixel sizes are rounded to whole pixels, so converting them back can differ by up to half a pixel.
- Photo-print, business-card and poster sizes are common conventions that vary by country and printer; check with your print shop.
- Passport and visa photo rules differ by country and change over time — always follow the official form or website.
- Bleed and safe-margin values differ between printers; the defaults here are common starting points, not requirements.
Privacy
Everything happens in your browser. What you enter or open here is not uploaded or stored by MySmartCoPilot.
Frequently asked questions
How many pixels is A4?
A4 (210 × 297 mm) is 2480 × 3508 px at 300 DPI, 1240 × 1754 px at 150 DPI, 794 × 1123 px at 96 DPI and 595 × 842 px at 72 DPI. Landscape swaps the two numbers.
What is A4 size in inches and centimetres?
A4 is 21 × 29.7 cm, which is 8.27 × 11.69 in (rounded to two decimals).
What is the difference between A4 and US Letter?
A4 is 210 × 297 mm; Letter is 8.5 × 11 in (215.9 × 279.4 mm). A4 is 5.9 mm narrower and 17.6 mm taller, so documents can lose a line or a margin when printed on the other size.
What DPI should I use?
Use 300 DPI for anything printed and viewed up close (photos, flyers, cards), 150 DPI for large posters, and 72 or 96 DPI for screen-only use. More pixels than that rarely look sharper on paper but make files much larger.
What size is a business card?
In the US and Canada, 3.5 × 2 in (88.9 × 50.8 mm) — 1050 × 600 px at 300 DPI, or 1125 × 675 px with a 1/8 in bleed. Much of Europe uses 85 × 55 mm, Japan 91 × 55 mm, and the ID-1 credit-card size is 85.60 × 53.98 mm.
Is anything I type sent anywhere?
No. Every conversion happens in your browser, and the page keeps working offline once it has loaded.