The shape and size of surface mount resistors ( SMD resistors ) are standardized, most manufacturers use the JEDEC standards. Surface mount resistors are available in all kinds of packages. The mostly used ones nowadays are rectangular.
 
Designing with surface mount resistors, a right solder pad size and land pattern should be used. The following table shows the land pattern for common surface mount packages. The table lists the dimensions for reflow soldering, for wave soldering smaller pads are used.


 
The size of chip resistor is indicated by a numerical code, such as 0805. This code contains the width and length of the package. Take 0805 for instance, it indicates a length of 0.080″ and a width of 0.050″. This code can be given in Metric or Imperial units. In modern PCB design metric units (mm) are more often used, while the Imperial code is used more often to indicate the package size. In general you can assume the code is in imperial units, but the dimensions used are in mm. The SMD resistor size depends on the required power rating mainly. The following table lists the dimensions and specifications of commonly used surface mount packages.
 The size of chip resistor is indicated by a numerical code, such as 0805. This code contains the width and length of the package. Take 0805 for instance, it indicates a length of 0.080″ and a width of 0.050″. This code can be given in Metric or Imperial units. In modern PCB design metric units (mm) are more often used, while the Imperial code is used more often to indicate the package size. In general you can assume the code is in imperial units, but the dimensions used are in mm. The SMD resistor size depends on the required power rating mainly. The following table lists the dimensions and specifications of commonly used surface mount packages.