design tool
Paper size converter
Pick a paper size, from A0 to A6, the B series, US Letter, Legal, Tabloid or DL, or type your own, and read it in millimetres, centimetres, inches and points, plus the pixel size at 72, 150 and 300 DPI and any other resolution you enter. A4, for example, is 210 by 297 mm, 8.27 by 11.69 inches, and 2480 by 3508 pixels at 300 DPI.
Loading the tool…
- Runs on your device, nothing is uploaded
- Free, no sign in
- No watermark, no file limit
How it works
- 1
Pick the size
Choose from the ISO A series, the ISO B series, North American sizes or DL. Choose Custom size to type a width and height in millimetres or inches.
- 2
Set the orientation
Portrait or Landscape swaps the width and height everywhere on the page.
- 3
Read the units and pixels
The top panel shows millimetres, centimetres, inches and points. The table shows pixels at 72, 150 and 300 DPI and at your own DPI, with the product's canvas sizes tagged.
- 4
Copy or compare
Copy these sizes takes the lot as text. Open Every size at once for the whole list side by side.
Why A sizes halve so neatly
ISO 216 gives every A size the same shape, a ratio of 1 to the square root of 2, which is the one shape that stays the same when the sheet is cut in half across its long side. A0 has an area of one square metre, A1 is half of it, and so on down, so two A4 pages side by side make exactly one A3. That is why a design scaled from A4 to A3 needs no cropping, and why the percentage is always 141. The B series sits between the A sizes, each B size being the geometric mean of the A sizes either side, which is useful for posters and books that need a size between two A sheets.
Letter, Legal and Tabloid
North America uses inch sizes that do not share a shape. Letter is 8.5 by 11 inches, 215.9 by 279.4 mm, a little wider and shorter than A4, so a page laid out for one loses a strip when printed on the other. Legal is the same width as Letter and 14 inches long. Tabloid, also called Ledger in landscape, is 11 by 17 inches, two Letter pages side by side. If one file will be printed in both regions, keep text and logos clear of the strips that differ, about 6 mm across the width and 18 mm down the length.
Pixels, DPI and the canvas sizes
A paper size in pixels only exists at a stated DPI: multiply the inches by the dots per inch and round. At 72 DPI the pixel numbers match PDF points, which is why an A4 PDF page reads 595 by 842. At 150 DPI, A4 is 1240 by 1754, which is the A4 canvas the flyer builder works on; flyers export at twice that, 2480 by 3508, which is A4 at 300 DPI and the usual figure printers ask for. The poster builder works at A0 on a 1656 by 2340 canvas, which is 50 DPI, and exports at twice that. The tool tags these numbers when your size produces them.
DL and one third of A4
DL is 99 by 210 mm, a third of an A4 sheet cut along its length, the format of rack cards and letterbox flyers. It takes its name from the DL envelope, 110 by 220 mm, which holds an A4 letter folded twice. Three DL flyers print on one A4 sheet, so a DL job costs about the same per sheet as A4 while giving three pieces.
Limits worth knowing
Pixel values are rounded, so 297 mm at 150 DPI gives 1754 pixels, not 1753.9; converting back gives 297.01 mm, which no printer will notice. The listed sizes are the finished trim sizes, without bleed. Nothing is uploaded and nothing is stored, ever.
Limits
- Pixel values are rounded to whole pixels, so converting back can be a fraction of a millimetre out.
- The flyer builder's A4 canvas is 1240 by 1754 pixels, which is A4 at 150 DPI, and its export is twice that.
- Custom sizes run from 10 mm to 5 m on each side; your own DPI from 1 to 2400.
What it does not do
- It does not resize or check an image; the DPI calculator and the PDF page size checker do those jobs.
- It does not add bleed. The bleed calculator gives the size with bleed and the safe area.
- It does not list envelope C sizes or photographic print sizes.
Questions people ask
What size is A4 in pixels for a website or a screen?
Screens do not have a fixed DPI, so A4 has no single pixel size for the web. A common choice is 794 by 1123, which is A4 at 96 pixels per inch, the CSS reference resolution. Use the Your own DPI box with 96 to see it. For print, use 300 DPI, which gives 2480 by 3508.
How many A4 pages fit on an A0 sheet?
Sixteen. Each step up the A series doubles the area, so A3 holds two A4 pages, A2 four, A1 eight and A0 sixteen, all at the same shape. That is why an A0 poster designed from an A4 layout scales by exactly 400 percent and why printers can gang sixteen A4 jobs onto one A0 sheet with no waste.
What are points, and why does a PDF page use them?
A point is one seventy second of an inch, the unit PDF and most typesetting use for page and type sizes. An A4 PDF page is 595.28 by 841.89 points, and a Letter page is exactly 612 by 792. The converter shows points for any size, which helps when a print shop or a script asks for the page size in points.
What size is A3 compared with A4?
A3 is 297 by 420 mm, exactly twice the area of A4 and the same shape, so A4 artwork enlarges to A3 at 141 percent with nothing cropped. At 300 DPI A3 is 3508 by 4961 pixels. It is a common size for small posters and menus, and two A4 pages placed side by side make one A3 sheet.
Does the converter use my files or send anything?
No file is involved: you choose a size and the page does arithmetic. No network request is made after the page loads, and nothing is stored, ever, so there is nothing to clear afterwards. The same numbers come out on any device, because none of them depend on your screen.
Start a flyer on the A4 canvas
Take what you made here into flyers.
Create a flyer with OneCraftMore tools like this
- Bleed calculatorA bleed calculator for any print size: enter the finished size and the bleed to get the document size, the safe area and pixels, with a labelled drawing.
- DPI calculatorEnter a pixel size and a print size and see the sheet drawn at real proportions, the area your file covers sharply, and a plain verdict on whether it will do.
- Aspect ratio calculatorType a size and see your shape drawn against any target: the bars if you fit it whole, the crop if you fill it. Presets for print, screen and social.
- PDF page size checkerDrop a PDF and read a print report: every page size named against ISO 216 and ANSI, trim box against media box, bleed in millimetres, rotation and clearance.
- Flyer size resizerDrop a flyer and see it refitted onto all ten builder canvases at once, each drawn at its true shape, with the ones that will print soft flagged in words.
Background reading: the question page on this.
Written and checked by the OneCraft team. Last checked .