A binary code symbol for non-linear strain measurement designed specifically for perimeter-based deformation and strain analysis. The symbol is rectangular with a continuous outer perimeter, two data regions along adjacent sides of the rectangle and a utility region adjacent each side opposite the data regions. Each data region is made up of at least two rows, each of which is made up of a number of data cells, and each utility region is made up of at least two rows, each of which is made up of utility cells with alternating appearance. There are at least two distinct finder cells on opposite corners of the rectangle, which can be used to orient the symbol. A non-linear strain gage for measuring the strain on an object under load in accordance includes a target, a sensor, and a computer, wherein the target is a binary code symbol.