About the Print Size Calculator
For a sharp print you need enough pixels for the size you want. This calculator works two ways. It takes the pixel size of a photo and the dpi you want and gives the size you can print, in inches and centimetres, with a quality rating. Or it takes the print size and dpi and says how many pixels the photo needs and how many megapixels that is. Type the pixels and dpi, or the print size and dpi and the print size appears at once, with a few related figures underneath, and you can copy the result with one tap. The sums run in your browser, so nothing you enter is uploaded.
Updated October 2026
How to use the Print Size Calculator
- 1Enter the pixels and dpi, or the print size and dpi.
- 2Pick the units or options from the menus if the print size tool offers them.
- 3Read the print size in the large result box.
- 4Look at the extra rows for related figures.
- 5Press Copy result to keep the answer.
When you need the print size
Photographers check whether a picture is big enough before they order a print or a canvas. Designers check images for flyers and posters, and parents work out whether a phone photo will make a decent print for the wall.
Posters seen from further away can use lower dpi: 150 is fine for a big print viewed from a couple of metres. A phone with 12 megapixels is enough for a sharp A4 print and a good enlargement up to A3.
How the print size is worked out
Print size = pixels ÷ dpi. Pixels needed = print size in inches × dpi. A 3,000 × 2,000 pixel photo prints at 10 × 6.67 inches (25.4 × 16.9 cm) at 300 dpi, which is excellent quality. An 8 × 10 inch print at 300 dpi needs 2,400 × 3,000 pixels, 7.2 megapixels.
Every answer on this page comes from that one rule, so you can check any result by hand with a calculator. The figures shown underneath, such as other units, are conversions of the same answer.
- Two directions
- Quality rating
- Inches and centimetres
Mistakes to avoid with print size
The dpi in a file's settings is only a label. What matters is the total pixels. Enlarging an image in software does not add detail, so a small photo stretched to a big print will look soft. If your photo is too small, take a new picture at a higher setting or print smaller.
On phone and computer
On a phone, type into the boxes one after another and read the print size underneath; Copy result puts it on the clipboard for a message or a note. On a computer the inputs sit on the left and the answer on the right, so you can change one figure and watch the print size move. The print size calculator works the same on both. Print size depends on pixels and density, so check both. Use the PPI Calculator for screen density, the Paper Size Converter for sheet sizes, and the Image Resizer when a photo needs more or fewer pixels.
Features
- Pixels, not file dpi, set quality
- Lower dpi for posters
- Upscaling adds no detail
- Clear messages when the print size inputs make no sense
- Copy the result with one tap
- Private: nothing is uploaded
Frequently asked questions
How do I calculate print size?
Print size = pixels ÷ dpi. Pixels needed = print size in inches × dpi. A 3,000 × 2,000 pixel photo prints at 10 × 6.67 inches (25.4 × 16.9 cm) at 300 dpi, which is excellent quality. An 8 × 10 inch print at 300 dpi needs 2,400 × 3,000 pixels, 7.2 megapixels.
What is the formula for print size?
Print size = pixels ÷ dpi. Pixels needed = print size in inches × dpi. The print size calculator applies it exactly and rounds only the displayed answer to six significant figures.
What dpi do I need for photos?
300 dpi for the sharpest prints at normal viewing distance; 150 to 200 dpi is fine for posters.
How many megapixels for an 8x10 print?
About 7.2 megapixels at 300 dpi.
Does upscaling help?
It makes the image bigger but not sharper. Pixels are interpolated, not recovered.
Is this print size calculator free and private?
Yes. It is free, needs no account and runs in your browser, so the numbers you type are not uploaded or stored.