Convert Dots per point to Pixels per centimetre

Convert Dots per point (dot/pt) to Pixels per centimetre (px/cm) instantly and accurately.

Conversion Formula

px/cm = dot/pt × 28.34645669

About Dots per point

The dot per point (dot/pt) expresses output resolution relative to the PostScript point - exactly 1/72 inch, codified by Adobe in the PostScript Language Reference (1985). The Apple Macintosh 128K (1984) ran its built-in CRT at exactly 72 DPI, placing 1 dot per point - an intentional WYSIWYG design: a 12-point character on screen measured 12 pixels tall and printed at 12 points on the Apple LaserWriter. Device resolution milestones: Apple LaserWriter (1985) 300 DPI = 300/72 ≈ 4.17 dot/pt; HP LaserJet 4 (1992) 600 DPI ≈ 8.33 dot/pt; Linotronic 300 imagesetter (1985) 1270 DPI ≈ 17.64 dot/pt; Agfa Selectset 5000 at 2400 DPI = 33.33 dot/pt. TrueType and OpenType font hinting instructions align outline points to raster device pixels at the current dot/pt ratio. The CSS pt unit equals the PostScript point: 1 CSS pt = 1/72 CSS in = 4/3 CSS px at 1 dppx. 1 dot/pt = 72 DPI = 72 PPI.

About Pixels per centimetre

The pixel per centimetre (px/cm) is the metric counterpart of PPI, measuring pixel density per centimetre. EXIF assigns ResolutionUnit = 3 when resolution is stored in px/cm; Canon, Fujifilm, and Nikon cameras can output EXIF data in px/cm. GIMP stores and displays image resolution in px/cm in its XCF format and Image Properties dialog. DICOM (NEMA PS 3.3) stores spatial resolution as PixelSpacing in mm/pixel; a radiograph at 0.2 mm/px = 5 px/mm = 50 px/cm = 127 PPI. At 10×15 cm print size, a 12 MP image (4000×3000 px) prints at 4000/15 ≈ 266.7 px/cm ≈ 677 PPI - well above the ISO 12647-2 minimum of ≈ 118 px/cm (300 PPI). Since 1 inch = 2.54 cm exactly, 1 px/cm = 2.54 PPI exactly. 1 px/cm = 2.54 PPI = 10 px/dm = 100 px/m.

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