Divide pixels by PPI
Width in inches = image width in pixels ÷ PPI. Apply the same calculation to height. Enter both dimensions into the pixels-to-inches converter and choose the intended image resolution. It calculates dimensions without changing the original image.
The same pixels at different sizes
| Image dimensions | PPI | Size in inches |
|---|---|---|
| 1200 × 1800 px | 300 | 4 × 6 |
| 1200 × 1800 px | 150 | 8 × 12 |
| 2400 × 3000 px | 300 | 8 × 10 |
Printing the same image larger spreads the available detail over more space. It does not create additional detail. Use your printer or publisher’s requested resolution rather than assuming one value fits every job.
Reverse the calculation
For a target width of 6 inches at 300 PPI, calculate 6 × 300 = 1800 pixels. A 4-inch height needs 1200 pixels. The calculator’s inches-to-pixels direction performs this calculation for both dimensions. Round non-integer pixel results when entering dimensions into an image editor.
Image resolution and PDF page size
A PDF page can hold an image at different physical sizes. Select a page size and margins that suit your document in JPG to PDF or Image to PDFJPEG to PNGJPEG to JPGPixels to inches. A larger page does not improve a small source image. Review the completed PDF at the intended print size before printing many copies.
Do not confuse screen pixels with image PPI
Browser layout uses CSS reference pixels; physical screen density and scaling vary between devices. A calculator based on your selected PPI cannot measure your monitor. See MDN’s CSS length documentation for screen and print unit behavior. Printer DPI concerns printer dots, while image PPI concerns image pixels.