Free calculator
Print size to required pixels.
Estimate the source pixel dimension needed for a chosen physical size and target PPI.
1,181 pixels
3.937 inches × 300 PPI
Formula
required pixels = printed inches × target PPI
A requirement is not a guarantee of sharpness. Focus, compression, motion blur, resampling and printer behaviour also affect the result.
Calculate width and height separately.
For a 10 × 15 cm print at 300 PPI, calculate 10 cm and 15 cm independently. The rounded requirements are approximately 1181 × 1772 pixels.
Use the main exact-size printer when you already have an image and want to see its effective PPI at a chosen output size.
Round up when preparing a new file
The calculator rounds to the nearest pixel. When designing from scratch, it is usually harmless to round upward to a convenient whole number. Extra source pixels do not force a larger physical print; the layout application still controls the physical size.
Do not upscale only to satisfy the number
Resampling a small image to a larger pixel count can make a file meet a numerical requirement without restoring real captured detail. Prefer a higher-resolution original, a smaller print size or a workflow that accepts the lower effective PPI.