SMD resistor sizes

The shape and size of surface mount resistors are standardized, with most manufacturers using the JEDEC standards. The size of SMD resistors is indicated by a numerical code, such as 0603. This code contains the length and width of the package. So, the imperial code 0603 indicates a length of 0.060" and a width of 0.030".

The SMD package code can be given in either imperial or metric units. In general, the imperial code is used more often to indicate the package size. Confusingly, even when the imperial naming convention is used, the metric dimensions are often used during the design of the printed circuit boards (PCBs). In general, you can assume the code is in imperial units, but the dimensions used are in mm. The SMD resistor size used depends primarily on the required power rating, the minimum feature size of the PCB manufacturing, and the limitations of the pick-and-place equipment. The following table lists the dimensions and specifications of commonly used surface mount packages.