Optimise Images for Print
Resize images to the exact pixel dimensions needed for professional 300 DPI print — no fiddly calculator required.
Print image sizing follows one rule that never changes: at 300 dots per inch, one inch of print is 300 pixels. That produces a simple conversion — A4 (210 × 297 mm) at 300 DPI is exactly 2480 × 3508 pixels, A3 is 3508 × 4961, US Letter is 2550 × 3300, and so on. Anything less than that, at any given size, will look visibly soft when printed.
The tricky bits aren't the pixel counts — they're the format, bleed and product-specific requirements. Business cards need 3 mm bleed. T-shirt DTG requires PNG with a transparent background. Canvas prints tolerate slightly lower DPI because the fabric weave already softens the image. Mug wraps have specific 2700 × 1050 templates. This hub organises every print preset in one place, with a page explaining each product-specific quirk.
For submitting to print shops (Instantprint, Prontaprint, Vistaprint, Snapfish, Photobox, Boots Photo, Bonusprint), start with the preset for your paper size, resize your source image accordingly, then hand the result to your print shop's upload tool. If you're unsure about bleed or ICC colour profiles, ask the shop directly — every shop has its own template preferences.
Paper sizes (A-series and US)
Presets for the standard A-series (A2 poster to A6 postcard) and US Letter, all at professional 300 DPI.
Photo prints
Standard photo-lab sizes for framed, gift and family portraits. Every UK photo lab uses these dimensions.
Products & speciality print
Canvas prints, T-shirts, mugs, flyers and business cards — each with product-specific format and dimension rules.
Related tools
Frequently asked questions
- Do I really need 300 DPI for print?
- For anything held in hand — postcards, business cards, flyers, photo prints — yes, 300 DPI is what separates professional-looking print from visibly soft output. Posters viewed from a distance (over 1 metre) can tolerate 200 DPI without a noticeable difference.
- My phone camera is 12 MP — can I print at A3?
- Yes. A 12 MP smartphone camera captures around 4000 × 3000 pixels natively, which just meets the A3 300-DPI requirement (3508 × 4961). Newer 48 MP phones (native output typically 8000 × 6000) easily produce A2 poster prints.
- What format should I send to the print shop?
- JPEG at maximum quality is universally accepted. Send PNG for designs with transparency (T-shirt DTG, mug wraps, sticker designs). For anything with subtle gradients or fine detail, ask your print shop if they prefer TIFF — most professional shops accept it.
- How do I add bleed?
- For any print with an edge-to-edge design, add 3 mm to each edge and export at the bleed-inclusive dimension. Your print shop's template usually specifies this — if unsure, ask them for the exact bleed dimension for the product you're ordering.
- Is anything uploaded when I use the tool?
- No. Every preset on this site runs in your browser. Your source photo (or your finished design) never leaves your device.