Image Resolution Calculator (PPI/DPI)
Written by Thierno Sadou Diallo, formula verified per our methodology • Last checked on 9/3/2026
An image's print size is found by dividing its pixel dimensions by its resolution in PPI (pixels per inch). Example: a 3000 × 2000 pixel photo printed at 300 PPI gives a maximum size of 10 × 6.67 inches, or about 25.4 × 16.9 cm.
Explanation
PPI (pixels per inch, or DPI, dots per inch, often used interchangeably in everyday usage even though the two terms technically describe slightly different things) expresses an image's pixel density when printed: the higher the number, the smaller and more tightly packed the pixels, and the sharper the result looks to the naked eye. The same digital image, with the same pixel count, can therefore print large but blurry (low PPI) or small but very sharp (high PPI) — resolution isn't fixed in the file, it's a destination setting chosen at print time. 300 PPI is the professional standard for a high-quality photo print viewed up close (a photo print, a magazine), while 150 PPI is enough for a poster viewed from a distance, and 72 to 96 PPI is the typical pixel density of a standard computer screen. This calculator answers the reverse question of a data conversion calculator (which converts a file size, not dimensions): from an image's pixel count and a target PPI, it gives the largest print size without a perceived loss of sharpness.
Example: a 3000 × 2000 pixel photo at 300 PPI
Inputs
Width: 3000 px. Height: 2000 px. Resolution: 300 PPI.
Calculation
Divide each pixel dimension by the resolution: width = 3000 ÷ 300 = 10 inches; height = 2000 ÷ 300 = 6.67 inches. In centimeters (× 2.54): 10 × 2.54 = 25.4 cm; 6.67 × 2.54 ≈ 16.9 cm.
Result
This photo can be printed at 300 PPI up to a maximum size of 10 × 6.67 inches (25.4 × 16.9 cm).
Frequently asked questions
What resolution should I choose for a quality print?
300 PPI is the professional reference for a photo print viewed up close (a print, a book, a magazine). For something viewed from farther away, like a poster or a sign, a lower resolution (150, or even 100 PPI) is plenty, since the eye can no longer distinguish individual pixels at that distance.
What happens if I print larger than the calculated size?
The image is still technically printable at a larger size, but the effective resolution drops below the target PPI: individual pixels become visible (a blurry or pixelated look), more noticeably the closer the print is viewed from.
Are PPI and DPI exactly the same thing?
Technically no: PPI (pixels per inch) describes the pixel density of a digital image, while DPI (dots per inch) describes the number of physical ink droplets a printer deposits per inch, a measure of the printing hardware rather than the file itself. In practice, the two terms are commonly used interchangeably in everyday language and consumer software, which this calculator also follows.