The imperial format for bricks refers to two historical dimensions. The old imperial brick size, which was introduced in 1872, measured 250 × 120 × 65 mm. It initially served as a standard for state buildings in the German. In 1875 the new imperial brick format was introduced, measuring 240 x 115 x 63 mm.
Today, however, the normal brick format in Germany (240 x 115 x 71 mm) is mostly used. These standardized dimensions were introduced to make construction more economical and standardized. Between 1850 and 1950, most of the bricks were made in the imperial clay brick size.