This invention provides an angle gauge that, when used in conjunction with a caliper or other linear measuring device, improves both the precision and ease with which angles can be measured and set by allowing the user accurately to measure and set angles in fractions of degrees. Using the gauge, an angle formed by the gauge may be determined or set by reference to the linear distance measured by the caliper. Calculations or tables can be used to convert the linear measurements into the angle setting or measurement with great accuracy, or the capacity to calculate the angle corresponding to the linear measurement can be built (i.e. programmed) directly into the device.