A4 Size in Pixels
2480 by 3508 at 300 dpi — the number print shops ask for, and the arithmetic behind it, which is simpler than it looks.
Runs on your device — images are never uploadedDrop your images here
or click to browse — as many as you like
JPG · PNG · WebP · HEIC
Enlarging past the original cannot add detail that was never captured. The tool says so when it happens rather than quietly handing back something softer.
How it works
Three steps, no account, and the image never leaves your computer.
Drop the image in
JPG, PNG, WebP or an iPhone HEIC. Several at once is fine — they all come out the same size.
The size is already set to 2480 by 3508
Change it if you need something else. Cover crops to fill, Contain fits the whole picture and pads the rest.
Check the preview, then save
The crop is shown before anything is written, so what you get is what you saw.
What people resize to this
A poster or a flyer going to a print shop
The size they ask for, produced without a design suite and without uploading the artwork anywhere.
A certificate or a diploma template
Full-page artwork at print resolution, ready to be filled in or turned into a PDF.
A scan that came out the wrong size
Phone scanning apps produce all sorts of dimensions. This puts one back to a true A4 page.
An image that has to fill a PDF page
Sized to A4 first, so the page comes out with no margin and no stretching.
A4 has no pixels until you choose a resolution
A4 is 210 by 297 millimetres. That is a physical size. It has no pixels at all until somebody decides how many pixels go into each inch — which is what dpi means, and why the question has more than one answer.
The arithmetic is one division and one multiplication. 210 mm is 8.268 inches and 297 mm is 11.693 inches, because an inch is 25.4 mm. Multiply each by the resolution you want:
| Resolution | A4 in pixels | What it is for |
|---|---|---|
| 72 dpi | 595 × 842 | Screen only. Also the point size a PDF measures an A4 page in |
| 150 dpi | 1240 × 1754 | Draft printing. Legible, and visibly soft up close |
| 300 dpi | 2480 × 3508 | The standard for anything that will be printed properly |
| 600 dpi | 4961 × 7016 | Archival scanning. Four times the file for detail few people can see |
When a printer asks for “A4 at 300 dpi”, 2480 by 3508 is the whole of what they mean.
| Size | Ratio | File limit |
|---|---|---|
| 2480 × 3508 px | 1:1.414 | none — this is a print size |
Why 300 and not some other number
It is about the eye, not the machine. At the distance a page is normally held, roughly 300 dots per inch is where a person stops being able to make out individual dots. Below it, edges start to look soft; above it, almost nobody can tell the difference. That is why the figure has barely moved in decades.
The whole A series is one shape
Every A size has the same 1:1.414 proportion — the square root of two, which is the only ratio that stays itself when you fold it in half. A3 folded is A4, A4 folded is A5, and the shape never changes.
Practically: an image sized for A4 fits A3 and A5 without re-cropping. Only the resolution changes. A3 at 300 dpi is 3508 by 4961; A5 is 1754 by 2480.
Resizing up does not add detail
This is the part that costs people a print run. If your image is 1000 pixels wide, resizing it to 2480 does not create the missing detail — it spreads what is there over more pixels. Printed at A4 it looks exactly as soft as it was, in a larger file.
300 dpi is a property of the original, not a setting applied afterwards. If the source is small, print it smaller.
If the destination is a PDF
An image at 2480 by 3508 fills an A4 page exactly. Turning it into a PDF afterwards keeps that page size, which is what most submission forms and print shops expect to receive.
Cover or Contain, and what each throws away
Two ways to fit one shape into another, and the tool offers both.
Cover fills the frame completely and crops whatever does not fit. Nothing is distorted and nothing is padded; some of the picture is simply gone. This is what you want almost always.
Contain fits the whole image inside the frame and fills the leftover space with a colour you choose. Nothing is lost, but the picture is smaller and there are bars. Right when the whole frame matters — a poster, a diagram, a design you cannot cut.
Neither ever stretches. An image squashed to fit is the one mistake that cannot be undone by looking at it again later.
Nothing is uploaded
The resizing happens in your browser using your own processor, so the image never leaves your machine. That is why there is no file-size limit, no queue and no account, and why a batch of forty is limited by your computer rather than by somebody’s free tier.
Common questions
What is A4 size in pixels?
It depends on the resolution, because A4 is a physical size. At 300 dpi it is 2480 by 3508 pixels; at 150 dpi, 1240 by 1754; at 72 dpi, 595 by 842.
Where does 2480 by 3508 come from?
210 mm and 297 mm divided by 25.4 gives 8.268 and 11.693 inches. Multiplied by 300 dots per inch, that is 2480 and 3508. The same two numbers at any other dpi give the sizes for that resolution.
Is 300 dpi always necessary?
For print, yes — it is what commercial printing assumes. For anything shown on a screen it is wasted: 72 to 150 dpi is plenty, and a 300 dpi image is several times the file for no visible gain.
Can I turn a small image into a 300 dpi one?
Not really. Enlarging spreads the existing detail over more pixels; it does not invent any. The image will be the right dimensions and will still print soft. The resolution has to be in the original.
More image tools
Every one of them runs on your device. No uploads, no accounts.