The Crack Width Gauge is a tool used to measure the width of cracks in concrete or other building materials.
The Crack Width Ruler is a simple and inexpensive crack width measuring tool that is similar in size to a standard credit card and is marked with a series of graduated lines, each representing a specific width. To use, simply place the gauge over the crack and find the line that is similar in width to the crack to read the crack width. The tool has a measurement range of 0.10 - 2.50mm or 0.004 - 0.100 inches.

Alternatively, the Crack Width Gauge (CW-01 1PC) from Mountlaser has 31 precision crack width values ranging from 0.1mm to 7.0mm and a 1mm scale resolution. Made of polycarbonate material, crack measuring gauge is rugged and suitable for indoor and outdoor use.

crack measuring gauge also features a parallax-free design with bottom printing that virtually eliminates parallax and measurement distortion. In addition, the product has a coefficient of thermal expansion α of 70 microns/meter/°C (between -30°C and +30°C).