Calculate DPI, PPI, print size from pixels, and pixels needed for a target print size. Essential for photographers, designers, and print professionals.
The DPI (Dots Per Inch) Calculator converts between pixel dimensions and physical print sizes at any resolution. Enter your image dimensions in pixels and target DPI to find the maximum print size, or enter your desired print size to find out how many pixels you need.
DPI defines how many dots of ink (or pixels on screen) fit in one inch. For printing, 300 DPI is the standard for professional quality. For web, 72 or 96 PPI is typical. Billboard printing may use as low as 15 DPI because viewing distance is large.
This calculator supports multiple units (inches, centimeters, millimeters), shows quality warnings based on DPI thresholds, and includes a reference table of standard print and paper sizes so you can quickly check whether your image has enough resolution for the job. It is a fast way to avoid a print that looks soft or pixelated. That helps before you send a file to print or publish it online.
Use this calculator before printing when you want to know whether an image has enough resolution for the target size. It is useful for photographers, designers, and print shops that need a quick pixel-to-print check without trial-and-error exports. That saves time when sizing artwork for a specific print format. It also makes it easier to compare different output sizes before you commit to one.
Print Size (inches) = Pixels / DPI. Required Pixels = Print Size (inches) × DPI. DPI = Pixels / Print Size (inches).
Result: 13.33" × 10.00" at 300 DPI
4000 ÷ 300 = 13.33 inches wide, 3000 ÷ 300 = 10.00 inches tall. At 300 DPI, this image can print up to about 13×10 inches at full quality.
The relationship between pixels, DPI, and print size is simple math but often misunderstood. A 6000×4000 pixel image at 300 DPI prints at 20×13.3 inches. The same image at 72 DPI would theoretically print at 83×55 inches — but at terrible quality because each pixel would be very large and visible.
The DPI metadata stored in image files (EXIF data) is just a suggestion to software. Changing DPI in Photoshop without resampling doesn't alter pixels — it only changes the default print size. Real resolution is always measured in pixels.
The further away a print is viewed, the lower the DPI requirement. A 300 DPI photo print looks sharp at arm's length. A poster viewed from 3 feet away only needs 150 DPI. A billboard viewed from 50+ feet may use 15-30 DPI. The formula is roughly: Minimum DPI ≈ 3438 / viewing distance (inches).
Standard photo sizes and their requirements at 300 DPI: 4×6 needs 1200×1800 pixels (2.2 MP), 5×7 needs 1500×2100 (3.2 MP), 8×10 needs 2400×3000 (7.2 MP), 11×14 needs 3300×4200 (13.9 MP), 16×20 needs 4800×6000 (28.8 MP), 24×36 needs 7200×10800 (77.8 MP).
300 DPI is the gold standard for professional photo printing. 150 DPI is acceptable for large prints viewed from a distance. For billboards, even 15-50 DPI works because viewers stand far away.
Technically no. PPI (pixels per inch) refers to screen resolution, DPI (dots per inch) refers to printer resolution. However, in common usage they're used interchangeably for image resolution.
12MP is about 4000×3000 pixels. At 300 DPI, that's only 13×10 inches. Printing larger requires upsampling, which degrades quality. For large prints, use cameras with 24MP or higher.
Standard monitors are 72-110 PPI. Retina/HiDPI displays are 200-300+ PPI. A 27-inch 4K monitor is about 163 PPI. An iPhone 15 Pro is 460 PPI.
DPI metadata alone doesn't change file size — pixel dimensions do. A 4000×3000 image is the same file size whether tagged as 72 DPI or 300 DPI. DPI only matters when you decide the physical output size.
72 PPI is the historical web standard. Modern high-DPI screens benefit from 2× images (144 PPI effective). The actual pixel dimensions matter more than the DPI metadata for web.