Convert A.U. of Length (a.u.) to Point (pt) instantly.
About these units
A.U. of Length (a.u.)
The atomic unit of length, also known as the Bohr radius unit in atomic units, is approximately 5.29177 × 10⁻¹¹ meters. It is defined as the radius of the lowest-energy orbital of the hydrogen atom, providing a natural scale for describing atomic and quantum mechanical systems. Atomic units were devised to simplify equations in quantum chemistry and atomic physics by normalizing fundamental constants such as electron charge, Planck's constant, and electron mass to 1. In this system, many equations become dimensionless and far easier to manipulate mathematically. The atomic unit of length is essential in molecular orbital calculations, quantum simulations, and the study of electron behavior in atoms and molecules. Its use reflects an approach to physics in which units are chosen to match the natural scales of the systems being studied.
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.