Convert X-unit (X) to Point (pt) instantly.
About these units
X-unit (X)
The X-unit is an extremely small length, approximately 1.002 × 10⁻¹³ meters, historically used to express X-ray and gamma-ray wavelengths. The unit was invented before modern standards for measuring electromagnetic wavelengths existed, allowing scientists to describe extremely short wavelengths without resorting to scientific notation. X-units were valuable in crystallography and atomic physics in the early 20th century, enabling precise description of spectral lines emitted by X-ray sources. Although modern practice has largely replaced the X-unit with the nanometer or picometer, it continues to appear in historical literature. The unit's existence highlights how scientific progress shapes measuring conventions. Once essential, the X-unit now serves as a bridge to the history of early atomic research.
Point (pt)
A point is a typographic unit traditionally equal to 1/72 of an inch (in digital typography) or 0.352777 mm. Historically, however, the point system varied widely across regions and printing houses. In the era of metal movable type, each foundry often produced its own proprietary sizes, making typefaces and point values incompatible between printers. The modern point was standardized largely due to the demands of the publishing industry and later digital systems, especially PostScript and desktop publishing software. The point became essential because typography requires extremely fine control over letter height, line spacing, and layout—far beyond what conventional measurement systems could easily express. Designers and typesetters rely on points to specify the sizes of fonts, the spacing between lines (leading), and the thickness of rules or strokes. In digital environments, the point remains foundational even though screen resolutions vary. Software uses points as virtual units that are converted into pixels depending on display density. Thus, the point bridges the traditional world of print with modern digital rendering, maintaining continuity in the long history of written communication.