Tool

Print size calculator

Pixels to inches and centimetres at 300, 240 and 150 PPI, and the pixels a print needs. pixels ÷ PPI = inches, and inches × 2.54 = centimetres. To go the other way, inches × PPI = pixels.
Runs in your browser. Nothing you type leaves this page.
1. Your image: what size will it print?
Print size of 3,000 × 2,000 px
PPIInchesCentimetres
300 PPI10 × 6.7 in25.4 × 16.9 cm
240 PPI12.5 × 8.3 in31.8 × 21.2 cm
150 PPI20 × 13.3 in50.8 × 33.9 cm
2. A print size: how many pixels does it need?

Width and height are matched in the order you enter them, so swap them if your image is portrait. Section 1’s pixel size is the image you start from.

These are calculated sizes, not print-quality guarantees. After upscaling, check the file at 100 % zoom before you send it to print. Enhance (AI) estimates additional detail. Contains AI-estimated detail. Look closely at faces, text and fine patterns.

Worked example

Without JavaScript the formula above still works. For an image 3,000 pixels wide:
3,000 pixels wide
WidthPrints at
3,000 px at 300 PPI10 in (25.4 cm)
3,000 px at 240 PPI12.5 in (31.8 cm)
3,000 px at 150 PPI20 in (50.8 cm)

PPI, DPI and the pixel count

PPI (pixels per inch) describes an image file: how many pixels land in each inch of paper. DPI (dots per inch) describes a printer’s dots. They are related but not the same number, and an image file carries PPI.
A PPI tag in a file is only a label for the print size. Changing it does not add pixels; the pixel count is what limits the print. To get more pixels, the image has to be upscaled, which calculates new pixels from the ones you have. How to upscale an image on a Mac walks through both Preview and MacnifyIt.
300 PPI is a common target for prints viewed up close. Large prints viewed from farther away are often made at lower PPI, and every print service states its own minimum, so ask yours for pixel dimensions and PPI.

Questions

How do I convert pixels to inches?

Divide the pixels by the PPI. 3,000 pixels at 300 PPI is 10 inches; multiply by 2.54 for 25.4 centimetres.

How many pixels do I need for a print?

Multiply the print size in inches by the PPI. A 24 × 16 in print at 300 PPI needs 7,200 × 4,800 pixels.

Does changing the PPI value make an image sharper?

No. The PPI tag only sets how big the pixels print. The image has the same number of pixels either way.

What does MacnifyIt do with these numbers?

MacnifyIt sets the output size as 2×, 4× or 8×, or as an exact width, height, longest side, fit within a box or percent, so you can enter the pixel size this page gives you. Output is capped at about 400 megapixels (about 200 for a 16-bit PNG or TIFF).

Need more pixels?

MacnifyIt enlarges to 2×, 4×, 8× or an exact size. 12 full-resolution exports free. Unlimited previews. No account, no time limit.
Download for Mac
See pricing