PX to MM Converter
Convert pixels to mm, cm and inches at any DPI to see how big an image will actually print, with paper size presets, bleed and safe margin — all calculated instantly in your browser.
Unit converter
Paper size
Bleed & safe margin
- Trim size210.00 × 297.00 mm · 2480 × 3508 px
- With bleed216.00 × 303.00 mm · 2551 × 3579 px
- Safe area204.00 × 291.00 mm · 2409 × 3437 px
Everything runs locally in your browser. Nothing is uploaded to any server — close the tab and your files are gone.
1000 px cheat sheet
How big a 1000 px wide image actually is once you pick a DPI:
| DPI | Millimeters (mm) |
|---|---|
| 72 | 352.78 mm |
| 96 | 264.58 mm |
| 150 | 169.33 mm |
| 300 | 84.67 mm |
| 600 | 42.33 mm |
Which DPI should I use?
- 72 DPI — legacy screen resolution (pre-Retina displays)
- 96 DPI — the CSS reference pixel used by browsers and UI design
- 150 DPI — draft-quality print, quick proofs
- 300 DPI — standard for print production (brochures, magazines)
- 600 DPI — fine art prints and large-format signage
How to use
Type your pixel size
Enter your image’s pixel width (or height) into the px row, and the mm, cm and inch rows update instantly.
Set the DPI you’ll print at
Pick a preset (72 / 96 / 150 / 300 / 600) or type a custom value. The same pixel count maps to a very different physical size depending on DPI.
Compare against a paper size
Select an ISO A or B size, US Letter, Legal or Tabloid, or a card/postcard preset to see whether your pixels cover the page at that DPI.
Check bleed and safe margin
If the image is headed to a print shop, set bleed and safe margin in mm to see the trim size, the size with bleed, and the safe area in both mm and px.
How large a file can actually print
Read this the opposite way round from a paper-size chart: start with the pixel count you were handed, and each row shows the physical size that file covers at three working resolutions. Compare the long edge first — if the long edge falls short of the piece, the short edge will too.
| Long edge (px) | 150 DPI | 300 DPI | 600 DPI | At 300 DPI that covers |
|---|---|---|---|---|
| 1080 | 182.88 mm | 91.44 mm | 45.72 mm | A little more than the 90 mm length of a business card — nowhere near an A6 postcard. |
| 1920 | 325.12 mm | 162.56 mm | 81.28 mm | The 148 mm short edge of A5 comfortably, but not its 210 mm length. |
| 2480 | 419.95 mm | 209.97 mm | 104.99 mm | The 210 mm width of A4, bar the hundredth of a millimetre rounding takes off — the usual full-page figure. |
| 3000 | 508.00 mm | 254.00 mm | 127.00 mm | Ten inches exactly: past the width of A4, still short of its 297 mm height. |
| 4000 | 677.33 mm | 338.67 mm | 169.33 mm | A full A4 page lengthwise with room to spare, and short of A3’s 420 mm. |
| 6000 | 1016.00 mm | 508.00 mm | 254.00 mm | Past the 420 mm long edge of A3, which is also the width of an A2 sheet. |
Millimetres come from mm = px ÷ DPI × 25.4, shown to two decimals. The table says nothing about whether the image is sharp: a photo upscaled to 6000 px holds no more detail than the file it was enlarged from, only more pixels.
Diagnosing an asset someone else supplied
A file lands in your inbox with a pixel size and no context. These four cases cover most of what arrives, and every one of them is settled by the same division.
- A 512 px logo for a 90 mm business card
The arithmetic512 ÷ 300 × 25.4 = 43.35 mm. Covering the card’s 90 mm width at 300 DPI takes 1063 px, so the file holds under half the pixels the job needs.
What to doAsk for the vector original rather than a bigger export of the same PNG — an SVG, EPS, PDF or .ai file has no fixed pixel size. If the raster is all that exists, place it small enough to stay at 300 DPI and build the layout around that. The mm to px converter turns whatever size you settle on back into pixels.
- A 1600 px slide export stretched across an A4 page
The arithmeticAcross A4’s 210 mm width the effective resolution is 1600 ÷ (210 ÷ 25.4) ≈ 193.5 DPI — visibly soft beside type set at 300 DPI on the same page.
What to doEither place it smaller, since at 300 DPI it covers 135.47 mm, or re-export the slide at a larger pixel size from its source file, which is the only move that adds real detail. Our A4 pixel reference lists the pixel counts a full A4 page asks for.
- A 900 px scan of a stamp or a signature
The arithmeticScanned at 600 DPI those 900 px represent 38.1 mm of paper. Place the same file at 300 DPI and it prints 76.2 mm wide — twice the size of the physical object, which is usually an accident rather than a decision.
What to doDecide the printed size first, then make the density tag agree: 900 px across 38.1 mm is 600 DPI, and across 76.2 mm it is 300 DPI. The DPI changer rewrites that tag without touching a single pixel.
- A 4000 px image for a backdrop one metre wide
The arithmetic4000 px across 1000 mm is 4000 ÷ (1000 ÷ 25.4) = 101.6 DPI. The same file at 300 DPI would cover 338.67 mm, roughly an A3 sheet.
What to doLarge-format work is viewed from a distance and printers routinely accept far less than 300 DPI at final size — but the figure is theirs to set, so ask rather than assume 100 DPI will pass. Our 300 DPI guide covers what the DPI number in a file does and does not promise.
Frequently asked questions
How many mm is 1000 px at 300 DPI?
At 300 DPI, 1000 px is 84.67 mm (about 8.5 cm), from mm = px ÷ DPI × 25.4. At 72 DPI the same 1000 px works out to 352.78 mm — over four times larger — because a lower DPI spreads the same pixels across more physical space.
How big will my 3000 px image print at 300 DPI?
Exactly 254 mm, or 25.4 cm — 10 inches on the nose, since 3000 ÷ 300 = 10 in. At 72 DPI the same file would print at roughly 1058 mm (over a meter), which is why the DPI you set here matters as much as the pixel count.
Why does the same pixel count give a different mm size at another DPI?
A pixel has no fixed physical size on its own — it only gets one once you assign it a resolution. DPI says how many of those pixels are packed into each inch, so raising the DPI shrinks the printed size for the same px count, and lowering it enlarges the print.
Is a screen pixel the same physical size as a print pixel?
No. A screen pixel’s physical size depends on the display’s own PPI and varies from monitor to monitor, while a print pixel’s size is whatever DPI you export at. This tool lets you pick the DPI so you can see the physical size before you print, not the on-screen size.
What DPI should I use to convert px to mm for a print file?
300 DPI is the standard for most print production like brochures and magazines. Use 150 DPI for a quick draft proof, and reserve 600 DPI for fine art prints or large-format signage viewed up close.
Can I get the size in cm or inches instead of mm?
Yes — the mm, cm, in and px rows are all linked, so typing a value into the px row updates the cm and inch rows in the same instant, with no extra steps.
How do I work out the effective DPI of an image at a given print size?
Divide the pixels by the size in inches: DPI = px ÷ (mm ÷ 25.4). A 1600 px image spanning a 210 mm page is 1600 ÷ 8.268, or about 193.5 DPI. It is this converter’s equation rearranged, so you can also find it by hand: enter the pixel count, then move the DPI until the mm result matches the size you need. Whatever DPI you land on is the effective resolution at that size.
The client sent a 512 px logo — is that enough for print?
At 300 DPI it prints 43.35 mm wide, which is fine for a small mark and not enough for anything spanning a card or a page. Enlarging the PNG will not rescue it, because upscaling invents pixels instead of recovering detail that was never captured. Ask for the vector original — .ai, EPS, PDF or SVG — since vector artwork has no fixed pixel size and stays sharp at any dimension.
Does scaling a placed image in InDesign or Illustrator change its pixel count?
No, it changes the effective resolution instead. Place a 3000 px image at 254 mm and it sits at 300 DPI; scale it down to 50% and the same 3000 px now cover 127 mm, which is 600 DPI. Scaling up runs the other way and is where soft prints come from — the layout program has no more pixels to work with than the file gave it.
What is the lowest DPI a large banner can get away with?
That depends on viewing distance and on the print shop, not on a universal number. Wide-format work is read from metres away, so resolutions well under 300 DPI at final size are normal, and some shops prefer files built at a fraction of full size to keep them workable. Get the requirement from the printer before you build the artboard, because once raster artwork is finished the pixel count is fixed.