The size(footprint) of flat chips such as ceramic capacitors and resistors is identified by a 4-digit size code.
This 4-digit size code is measured in either MILLIMETERS or INCHES, which can cause confusion, so it’s important to verify whether the size code is in METRIC OR INCHES.
The first two digits in the size code refer to the length (L) from Termination-to-Termination. The second two digits refer to the width (W) of termination.
Inch Metric Inch Metric
008004 0201* 0.098“ x 0.049″ 0.25 x 0.125mm
n.a. 03015 0.012″ x 0.006″ 0.30 x 0.15mm
01005 0402* 0.016″ x 0.008″ 0.4 x 0.2mm
0201 0603* 0.024″ x 0.012 0.6 x 0.3mm
0402 1005* 0.04″ x 0.02″ 1.0 x 0.5mm
0504 1210* 0.05″ x 0.04″ 1.2 x 1.0mm
0603 1508 0.06″ x 0.03″ 1.5 x 0.8mm
0805 2012 0.08″ x 0.05″ 2.0 x 1.2mm
1005* 2512 0.10″ x 0.05″ 2.5 x 1.2mm
1206 3216 0.12″ x 0.06″ 3.2 x 1.6mm
1210* 3225 0.12″ x 0.10″ 3.2 x 2.5mm
1812 4532 0.18″ x 0.12″ 4.5 x 3.2mm
2225 5664 0.22″ x 0.25″ 5.6 x 6.4mm
Caution: Overlapping size codes. Metric appears same as inches.