Relationship Between Imperial and Metric Surface-Mount Resistor Packages, with Detailed Dimensions. There are nine common package types for surface-mount (SMD) resistors, which are identified using two different sets of size codes. One system uses a four-digit code—the EIA (Electronic Industries Alliance) standard—where the first two digits represent the length and the last two represent the width, measured in inches. For example, the "0603" package designation refers to this imperial-based coding system. Another system uses imperial-based codes. The following table lists common SMD (surface-mount device) resistor package sizes in both imperial and metric units, along with their detailed dimensions: Imperial (inch) | Metric (mm) | Length (L) (mm) | Width (W) (mm) | Height (t) (mm) | a (mm) | b (mm) | 0201 | 0603 | 0.60±0.05 | 0.30±0.05 | 0.23±0.05 | 0.10±0.05 | 0.15±0.05 | 0402 | 1005 | 1.00±0.10 | 0.50±0.10 | 0.30±0.10 | 0.20±0.10 | 0.25±0.10 | 0603 | 1608 | 1.60±0.15 | 0.80±0.15 | 0.40±0.10 | 0.30±0.20 | 0.30±0.20 | 0805 | 2012 | 2.00±0.20 | 1.25±0.15 | 0.50±0.10 | 0.40±0.20 | 0.40±0.20 | 1206 | 3216 | 3.20±0.20 | 1.60±0.15 | 0.55±0.10 | 0.50±0.20 | 0.50±0.20 | 1210 | 3225 | 3.20±0.20 | 2.50±0.20 | 0.55±0.10 | 0.50±0.20 | 0.50±0.20 | 1812 | 4832 4.50±0.20 3.20±0.20 0.55±0.10 0.50±0.20 0.50±0.20 2010 5025 5.00±0.20 2.50±0.20 0.55±0.10 0.60±0.20 0.60±0.20 2512 6432 6.40±0.20 3.20±0.20 0.55±0.10 0.60±0.20 0.60±0.20 These dimensions apply to both SMD capacitors and SMD resistors. For SMD resistors and capacitors (such as 0805, 1206, etc.), the relationship between package size and power rating is generally as follows: 0201: 1/20W, 0402: 1/16W, 0603: 1/10W, 0805: 1/8W, 1206: 1/4W. The correspondence between physical dimensions and package codes for capacitors and resistors is: 0402 = 1.0x0.5, 0603 = 1.6x0.8, 0805 = 2.0x1.2, 1206 = 3.2x1.6, 1210 = 3.2x2.5.