An architect scale is used for taking measurements from reduced scale drawings like blueprints. Once made of wood, the material used in architect's scale in present times is aluminium or rigid plastic. In Britain, architectural drawings are measured in standard units like millimetres and meters.

There are 3 sides to an architect's scale and there is a ruler on every side. One can read fractions of an inch in the architect's scale too. For example ½" can be read as one feet. To begin with, look for the scale on your blueprint. It is found on the bottom left hand corner of the page. After this, look for the corresponding measurement, on the ruler. The scale has a long mark towards the left of a '0' which is the beginning of the feet, and shorter marks on the right side of '0' which represent the inches. Keep the ruler straight with the '0' mark on the starting point of the part you want to take measurement of. The closest mark the lines pass through is the foot measurement.