Squirrel Tactile Caliper

The Tactile Caliper is an excellent measuring device developed by Pranay Jain and Anshul Singhai from MIT. Using the caliper, students who can read Braille numbers can measure and draw with precision and speed. 

This product was field tested with students by Janet Ulwick-Sacca, an experienced teacher of the visually impaired, who also served as a mentor on the project. 

This is a Youtube video of the product in action:




This caliper will be useful in all STEM classrooms, enabling students with a visual impairment to easily accomplish a variety of measuring tasks with a precision not possible in the past. 

The caliper is accurate to 1/16”. There are subtle audible cues when it is operating. The caliper is 12 inches long, the size of a standard ruler.  The caliper's design allows for small objects to be inserted into the caliper’s opening.  This eliminates some common problems for students including holding the ruler steady and lining up the ruler to begin measuring.


The tactile caliper is not yet available in centimeter measurements. It can only easily measure objects 12 inches or less in size.

Ordering Info: 

 The caliper is available from National Braille Press.