Questions, answered
Short answers to the questions people actually ask about DPI, PPI, and printing. Each one links to the tool or explanation with the full detail.
THE BASICS
PPI counts image pixels per inch — the density of your file at a placed size. DPI counts the dots a printer lays down. Print shops often say “DPI” when they mean the image side, but they measure different things.
See the exact definitions →No. Pixels are the detail; the DPI tag is a print-size hint. Changing the tag never adds detail.
What a tag change actually does →Changing the metadata tag is lossless but adds no detail. Resampling (upscaling) adds pixels but not real detail, so enlargements soften.
Change a tag safely →The 72 tag alone cannot tell you anything. Judge the effective PPI at your placed print size, not the header number.
Calculate effective PPI →No. Browsers size images by pixel dimensions and ignore density tags entirely.
Check what your file carries →The 300 was likely the tag, not the effective PPI at placed size. Focus, compression, and paper also limit sharpness.
Find the real effective PPI →PRINTING
Divide your pixel dimensions by the target PPI. 3000 × 2000 px gives 10 × 6.67 inches at 300 PPI.
Convert your pixels →A 24 MP camera (6000 × 4000) prints 20 × 13.3 inches at 300 PPI uncropped — more than enough for standard photo sizes.
Sensor-to-print chart →No. Viewing distance rules: wall art viewed from several feet is fine at 100–150 PPI; a one-arcminute estimate is PPI ≈ 3438 ÷ distance in inches.
Viewing-distance table →Bleed is artwork extending past the trim so cutting shifts never show white edges. Follow your printer’s template; the fit calculator can compute pixels including bleed.
Compute pixels including bleed →Exactly 2400 × 3000 pixels. A 3:2 camera photo needs cropping to the 4:5 paper ratio.
Work backward from any size →Requirements vary by provider and product — some ask for a 300 tag, others judge effective PPI. Check the provider’s current template; no tag guarantees acceptance.
Set a required tag →YOUR FILES
Windows: right-click → Properties → Details. macOS Preview: Tools → Show Inspector. Careful — MS Paint shows your monitor’s setting, not the file’s tag.
Check it in your browser instead →The file has no usable density tag, which is normal for screenshots and social downloads. Pixel dimensions still tell the whole quality story.
Read your file’s metadata →Yes, losslessly — the tag changes, pixels stay byte-identical. But if the effective PPI at placed size is low, no tag will fix it.
Change the tag locally →JPEG stores it in JFIF or EXIF headers, PNG in a pHYs chunk, BMP in header fields. WebP and GIF have no reliable density tag.
See what your format carries →Not here. The changer edits header bytes only — the compressed image data stays byte-for-byte identical.
Try a metadata-only edit →Cameras tag exports with a legacy display default. It says nothing about sensor quality — check pixel dimensions.
Check your photo →DISPLAYS
Desktop monitors run roughly 90–220 PPI; modern phones 400–460 PPI. It depends on resolution and physical size, not brand.
Calculate a display’s PPI →No. Browser zoom and Windows/macOS scaling resize interface elements; the panel’s physical pixel density never changes.
How PPI is measured →The center-to-center distance between pixels, in millimeters: 25.4 ÷ PPI. Smaller pitch means a sharper panel.
Compute pitch for any screen →An Apple marketing term, not a fixed threshold. Whether pixels are visible depends on viewing distance and eyesight — roughly 3438 ÷ distance in inches is the estimate.
Compare display densities →Allow Google Analytics to measure page visits? Images and calculator inputs stay on your device. Privacy details