250mm

250 millimeters (mm) is a unit of length in the metric system. It equals 0.25 meters and 25 centimeters, and is approximately 9.84 inches.

In technical disciplines, 250 mm is a practical dimension used to specify lengths, widths, or distances. It commonly appears in mechanical drawings and manufacturing tolerances, where dimensions are expressed in millimeters. Measuring tools such as metric rulers and calipers provide mm-scale readings, with many instruments offering sub-millimeter resolution for precision work.

Applications include the length of panels or parts, the spacing of holes, tile and sheet metal sizing, and other components where a quarter-meter scale is convenient. The choice of 250 mm as a dimension can help align with standardized manufacturing processes and part inventories that use metric units.

In photography and optics, 250 mm can denote a focal length of a telephoto lens, producing magnification suitable for distant subjects.

Conversion and relation: 250 mm equals 25 cm (0.25 m) and about 9.84 inches. The prefix milli- denotes one-thousandth; thus 250 mm equals 250,000 micrometers. The symbol mm is used after the numerical value without a space in most technical writing.